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Biomedical subjects

M Yamagata

Publications and source records attributed to M Yamagata.

171 records · Page 10Linked to original sources
PubMedDate not supplied

Gastric cancer in a general hospital in Japan.

During 20 years from 1971 to 1990, 605 patients with gastric cancer were treated by gastric resection at a medium-size general hospital by one surgeon. The overall 5-year survival rate was 61.9%. The 5-year survival rates in the first 10 years (n = 261) and the second 10 years (n = 344) were 53.7% and 67.9%, respectively (P < 0.01). In the second 10 years there was a significant increase in the patients with early gastric cancer (P < 0.01). Meanwhile, operative procedure or R2 or R3 lymph node dissection did not show any improvement of the 5-year survival rates. These results indicate that the prognosis for gastric cancer was relatively good at a general hospital which does not specialize in cancer research, and that much of the improvement in the prognosis could be attributed to the increase in the incidence of patients with early gastric cancer.

Female↗
PubMedDate not supplied

Effects of doxorubicin and/or cilostazol on cancer cells during liver regeneration after two-thirds hepatectomy in rats.

A rat model of liver metastases generated by intraportal injection of syngeneic tumor cells after two-thirds hepatectomy to determine the optimal benefit of doxorubicin and/or cilostazol for early hepatic metastases. Four groups of WKA rats had viable tumor cells injected directly into the portal vein after two-thirds hepatectomy. Group A underwent to further treatment. Group B had doxorubicin injected 24 h post-operatively. Group C had cilostazol administered prior to two-thirds hepatectomy. Group D received cilostazol, and doxorubicin injections. The mean survival period in each group was 22.2, 20.0, 28.8, and 22.8 days, respectively. The mean survival was significantly longer in group C than in groups A, B and D (p < 0.05). Based on these findings, we believe that during the phase of liver regeneration adjuvant chemotherapy is not recommended. Cilostazol exerts an important antiproliferative effect on liver metastases after hepatectomy.

Animals↗
PubMedDate not supplied

A comparative study on effects of doxorubicin alone or mixed with lipiodol given through the hepatic artery or portal vein for liver tumors in rats.

Vascular feeding of metastatic liver tumors at early stage is uncertain. It is controversial whether anticancer agents should be given through the hepatic artery or portal vein. In order to clarify this point, a rat model of liver metastases generated by an intraportal injection of syngeneic tumor cells was used to determine the optimal regional chemotherapeutic modality for early hepatic metastases. The rats given the tumor cells through the portal vein were placed into 5 groups: In groups I and II, Adriamycin (ADR) 4 mg/kg alone was given either into the hepatic artery or into the portal vein, respectively, 24 h after the inoculation of tumor cells. In groups III and IV, ADR mixed with lipiodol (lipiodolized ADR) 4 mg/kg was given into the hepatic artery or into the portal vein, respectively, 24 h after inoculation. For the group V rats, no treatment was given after inoculation of the tumor. When a comparison was made with regard to the forms of anticancer drug administered, statistically significant differences in survival rates were recognized between groups I and III (p < 0.001), and groups II and IV (p < 0.05). The anticancer agent not mixed with lipiodol and given through the hepatic artery had a more preventive effect than that given through the portal vein. Thus, we conclude that administration of ADR not mixed with lipiodol and given through the hepatic artery is the preferred modality for treating early metastatic liver tumors.

Animals↗
PubMedDate not supplied

Clinicopathological analyses of advanced colorectal cancers of different sizes--especially those of 20 mm or less in diameter.

BACKGROUND/AIMS: Many small cancers of the flat type can now be detected, and many advanced cancers of the flat type have been discovered. In this study, to clarify the clinicopathological characteristics of small advanced cancers, advanced cancers of 20 mm or less in diameter were compared with those of other sizes. METHODOLOGY: Patients with advanced colorectal cancer (n = 865) were divided into four groups on the basis of cancer diameter as follows: Group A (20 mm or less), 21 patients; Group B (21-60 mm), 581 patients; Group C (61-100 mm), 215 patients; and Group D (101 mm or more), 48 patients. These groups were compared for various clinicopathological findings. RESULTS: The depth of invasion was muscularis propria in 14 cases and subserosa in 7 cases. In Group A, cancer was histologically well-differentiated in 8 cases, moderately differentiated in 12 cases, and mucinous in one case. Six cases (28.6%) in Group A had lymph node metastasis (N1). In Group A, one patient had multiple liver metastasis and all of the other cases were assessed as R0 resection. CONCLUSIONS: Most small advanced colorectal cancers of 20 mm or less in diameter can be regarded as quasi-early cancers, but some have the potential for high malignancy, and for these, reduction surgery cannot be used.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Role of eicosapentaenoic acid in lipid metabolism in the liver, with special reference to experimental fatty liver.

Choline-deficient feed was given to three groups (n = 7 in each) of male Sprague-Dawley rats for 4 weeks to induce the development of fatty liver. In addition, two of the groups received eicosapentaenoic acid (EPA), 1000 mg/kg/d, administered orally either for all 4 weeks or for only the last 2 weeks of the study, respectively. The third group received the choline-deficient diet but no EPA. The untreated control group (n = 7) received only normal feed. The efficacy of EPA in preventing fatty liver was assessed based on the evaluation of pathologic and biochemical parameters and hepatic blood flow. EPA markedly improved fatty liver, probably due to both direct effects (inhibition of the synthesis of triglyceride in the liver) and indirect effects (increased hepatic blood flow). Decreased blood flow due to sinusoidal block is responsible for the progression of fatty liver. EPA has been shown to decrease thromboxane A2 production and blood viscosity and to enhance red cell deformability. These effects are thought to have contributed to the increases in hepatic blood flow.

Animals↗
PubMedDate not supplied

Surgical results of spontaneously ruptured hepatocellular carcinoma.

Seventeen patients with ruptured hepatocellular carcinoma (HCC) underwent a hepatic resection from 1985 to 1992 at either Kyushu University Hospital or Iizuka Hospital in Japan. They all underwent elective surgical procedures except for one patient who experienced a repeated rupture during hospitalization. A comparative study between the patients with ruptured HCC and non-ruptured large HCC measuring more than 6 cm in size (n = 29) revealed that the 3-year disease-free survival rate of the ruptured HCC group was 14.5% which was worse than that of the non-ruptured group at 39.9%. There was no difference in the rates of peritoneal dissemination, distant metastasis or intrahepatic recurrence between the two groups. Regarding the intrahepatic recurrence pattern, widespread multinodular recurrence frequently occured in the ruptured patients, which was thought to be caused by the high incidence of venous invasion in the primary tumor. The intratumor pressure of the ruptured HCC appeared to be elevated and is considered to be one of the main reasons for the high incidence of venous invasion.

Adult↗
PubMedDate not supplied

Early recurrence after surgery of hepatocellular carcinoma.

BACKGROUND/AIMS: In 231 patients with hepatocellular carcinoma who underwent liver resection from 1986 to 1992 to determine the significance of alpha-fetoprotein (AFP) levels. MATERIALS AND METHODS: There were 13 patients (5.6 per cent) with early recurrence within six months after hepatectomy. RESULTS: Preoperative serum alpha-fetoprotein (AFP) levels were significantly higher in patients with early recurrence (p < 0.01). Postoperative histological examination revealed that there were significant correlations between patients with early recurrence and intrahepatic metastasis (p < 0.01), and portal vein infiltration (p < 0.01). There were significant correlations between patients with early recurrence and preoperative diagnosis of intrahepatic metastasis (p < 0.01), however, preoperative diagnosis of portal vein infiltration could not be detected enough. Eight (73%) of 11 patients with over 1000 ng/ml of AFP and preoperative diagnosis of intrahepatic metastasis had early recurrence (p < 0.01). CONCLUSIONS: We found that patients of hepatocellular carcinoma with over 1000 ng/ml of AFP and preoperative diagnosis of intrahepatic metastasis are the most important factors in the preoperative clinical data linked to early recurrence type of HCC after hepatectomy.

Aged↗
PubMedDate not supplied

Small hepatic nodules surrounding hepatocellular carcinoma.

BACKGROUND/AIMS: We investigated whether or not small hepatic nodules surrounding the main hepatocellular carcinoma were malignant, while also analyzing the role of intraoperative ultrasonography in detecting these small nodules. MATERIALS AND METHODS: Thirty-three small hepatic nodules near the main tumor in 17 patients were retrospectively studied. They were first detected either during or after the operation using intraoperative ultrasonography and/or after examining a cross-section of the resected specimen. RESULTS: Twenty-six of the 33 small nodules were shown to be malignant when studied histologically (79%). The reliability of intraoperative ultrasonography was higher than 80 per cent for detecting nodules measuring more than 5 mm in diameter. However, it was only 25 per cent reliable with smaller nodules measuring less than or equal to 5 mm. CONCLUSIONS: These results suggest that most small hepatic nodules with hepatocellular carcinoma should be considered to be malignant. In addition, smaller nodules measuring less than 5 mm in size can hardly be detected by intraoperative ultrasonography.

Carcinoma, Hepatocellular↗