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Biomedical subjects

Y Hiramoto

Publications and source records attributed to Y Hiramoto.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Significance of splenectomy in the treatment of cancer].

With inoculation of a large amount of tumor cells, the tumor growth of splenectomized mice was depressed compared to sham operated mice. On the contrary, with inoculation of a small amount of tumor cells the occurrence of tumor was lower in sham-operated mice. The effect of splenectomy on tumor growth was bidirectional depending on the dose of the inoculate. The effect was due to the production of the immunosuppressive factor in sera obtained from mice inoculated with a large but not small amount of tumor cells. Studies for the late survivals of 113 patients who had received curative total gastrectomy with or without splenectomy revealed that the non-splenectomized group showed a significantly better late survival rate than the splenectomized group when the splenic hilar lymph nodes were not involved with cancer metastasis.

Animals↗
PubMed1982

Postoperative long-term cancer chemotherapy (PLCC) extends life-span of non-curatively resected patients with stage IV gastric cancer.

Postoperative long-term cancer chemotherapy (PLCC) with a combination of Mitomycin-C, Tegafur and PSK (an immunostimulant) was applied to non-curatively resected cases with stage IV gastric cancer (invading the adjacent organs and/or with metastasis to the liver, peritoneum, and/or distant lymph nodes). This approach has a significant life-prolongation effect. The two-year survival rate was 16.8 per cent in the PLCC group, such being higher than 6.7 per cent and 1.7 per cent in MMC and no chemotherapy groups (p less than 0.05). 50 per cent survival periods in those with liver metastasis were 8.3 months in the PLCC group, such being longer than 5.2 and 2.8 months in MMC and no chemotherapy groups (p less than 0.002) respectively. Combination therapy of PLCC and intra-arterial infusion of 5-FU through the proper hepatic artery prescribed for 8 patients with liver metastasis resulted in a 3-month prolongation of 50 per cent survival periods, compared with PLCC alone (p less than 0.05). In those with peritoneal dissemination the rate was 10.5 months in the PLCC group, that is longer than 6.5 months in the MMC group (p less than 0.02). In cases of invasion to other organs plus distant lymph node metastasis, the time was 11.0 in PLCC and 7.0 months in MMC groups (p less than 0.05). Thus, PLCC is a palliative approach for non-curatively resected carcinoma of the stomach.

Antineoplastic Agents↗
PubMed1982

Serial determinations of carcinoembryonic antigen for early detection of recurrent gastric cancer.

In attempts to predict the recurrence of gastric cancer, postoperative changes in serum carcinoembryonic antigen (CEA) levels are monitored in our clinic by radioimmunoassay (Dainabot, Japan). Recurrences are suspected when serum CEA levels are 4 ng/ml, in the postoperative period. Out of 34 patients in whom there were increases in serum CEA, 18 were confirmed to have a recurrence and 15 of these 18 patients were assessed accurately by serial postoperative levels of CEA, two patients died of a recurrence after elevation of serum CEA levels. Thus, recurrence was predicted in 17 out of 34 patients (50 per cent) and in 12 out of 17 patients there was a metastasis to the liver. In 14 out of 34 patients there are no signs of recurrence 9 to 25 months after serum CEA elevations.

Adenocarcinoma↗
PubMed1982

Rheological properties of echinoderm eggs during cell division.

Mechanical properties of the cell before and during cleavage in sea urchin eggs (a typical equal symmetrical cytoplasmic division) and polar-body formation (a typical unequal cytoplasmic division) are reviewed with special reference to the mechanism of cell division. Both in sea urchin eggs and starfish oocytes, the tension at the cell surface gradually increases before the onset of cytoplasmic division. The tension gradually decreases during division in starfish oocytes and in some sea urchin eggs. Some other sea urchin eggs display two peaks of the tension, one just before the onset of division and the other during division. The cleavage furrow is formed by the active contraction of a layer formed in the equatorial cortex of the cell in sea urchin eggs and of a ring-shaped layer formed in the cortex around the animal pole of the cell in starfish oocyte.

Animals↗
PubMed1982

[Effect of postoperative long-term cancer chemotherapy (PLCC) on non-curative gastric cancer of stage IV].

We studied the effect of postoperative long-term cancer chemotherapy (PLCC) on the survival of the patients with stage IV gastric cancer, subjected to non-curative resection. The study was carried out with 90 patients receiving the PLCC from 1970 to 1978, and 95 patients received intraoperative one shot I.V. injection of Mitomycin-C from 1964 to 1978, and 106 patients without chemotherapy from 1964 to 1970. The PLCC consisted of the following combination: MMC intermittent intravenous injection (20 mg of MMC during operation followed by 10 mg on the next day, 4th week and every 3 months respectively): postoperative oral administration of FT-207 (600 mg/day) and; PSK (3 g/day) for more than 4 months after operation. The background factors were not significantly different among 3 groups. Two year survival rate was 18.9% in PLCC group, significantly higher than that of 7.4% in MMC group and 2.0% in no chemotherapy group which was respectively (P less than 0.05). The PLCC also demonstrated its be effective mess in prolonging the survival of the patients with hepatic metastasis or peritoneal dissemination.

Antineoplastic Agents↗
PubMed1981

Quantitative studies on the polarization optical properties of living cells. I. Microphotometric birefringence detection system.

A method of polarization optical analysis is described in which phase retardation attributable to birefringence of a minute area in a microscopic object is determined. The optical system consists of a polarizing microscope with "rectified" strain-free lenses, a photoelectric detector to determine the intensity of the light passing through a minute window located at the image plane of the specimen, and a stage that moves the specimen at appropriate velocities for scanning. The error resulting from any flare of light emerging from outside of the area to be measured is minimized by limiting the illuminated area. The specimen can be observed during the measurement of light intensity by illuminating the whole microscope field at a wavelength different from that of the light used for the measurement. The retardation of the specimen is determined by comparing the specimen and background intensities as functions of the azimuth of a Brace-Köherl compensator. Alternatively, retardation is obtained directly from the light intensity at a fixed compensator angle, using the theory of polarization optics. The basal noise level for the present apparatus is approximately 0.03 nm when measuring birefringence of a 4-micron2 area in 0.1 s, using a X 40, NA 0.65 objective. The noise decreases in inverse proportion to the square root of the area times the duration of measurement.

Animals↗
PubMed1981

Quantitative studies on the polarization optical properties of living cells II. The role of microtubules in birefringence of the spindle of the sea urchin egg.

Birefringence of the mitotic apparatus (MA) and its change during mitosis in sea urchin eggs were quantitatively determined using the birefringence detection apparatus reported in the preceding paper (Hiramoto el al., 1981, J. Cell Biol. 89:115-120). The birefringence and the form of the MA are represented by five parameters: peak retardation (delta p), through retardation (delta t), interpolar distance (D1), the distance (D2) between chromosome groups moving toward poles, and the distance (D3) between two retardation peaks. Distributions of birefringence retardation and the coefficient of birefringence in the spindle were quantitatively determined in MAs isolated during metaphase and anaphase. The distribution of microtubules (MTs) contained in the spindle is attributable to the form birefringence caused by regularly arranged MTs. The distribution coincided fairly well with the distribution of MTs in isolated MAs determined by electron microscopy. Under the same assumption, the distribution of MTS in the spindle in living cells during mitosis was determined. The results show that the distribution of MTs and the total amount of polymerized tubulin (MTs) in the spindle change during mitosis, suggesting the assembly and disassembly of MTs as well as the dislocation of MTs during mitosis.

Animals↗
PubMed1979

[Gas flow (3)].

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Animals↗