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S Maetani

Publications and source records attributed to S Maetani.

At least 37 records · Page 2Linked to original sources
PubMed1992

Extensive en bloc resection of regionally recurrent carcinoma of the rectum.

To remove regionally recurrent cancer of the rectum completely, more radical extensive resections were attempted than the conventional ones in 35 patients. Twenty-two patients underwent total pelvic exenteration. In 23, sacral resection was done, combined with other procedures including excision of the entire circumference of the lower pelvic ring. There were two hospital deaths. Delayed wound healing was seen in ten. Preoperative severe pain was alleviated in 18. Also, perineal ulcer, vaginal bleeding, bloody stools, and tenesmus disappeared. Of the four 5-year survivors (estimated rate, 23%), only one was disease-free. A second recurrence was seen in 27 patients, of whom 23 had regional failure. It was concluded that so-called local recurrence is a lesion more widespread than indicated by imaging and biopsy. Therefore, even the most radical resection rarely can cure this disease. However, such a surgical procedure can afford more effective palliation than other treatments and may prolong life in selected patients significantly.

Adenocarcinoma↗
PubMed1992

Predictive factors for intrahepatic recurrence of hepatocellular carcinoma after partial hepatectomy.

To establish useful predictors of the intrahepatic recurrence of hepatocellular carcinoma (HCC) after partial hepatectomy, retrospective analyses of clinical and pathologic factors were done in 112 of 206 patients treated by partial hepatectomy. The absence or presence of intrahepatic recurrence was confirmed by a follow-up study. Cancer-free survival rates after 1, 2, 3, and 5 years were 54.8%, 36.7%, 32.5%, and 25.6%, respectively. The significant factors affecting recurrence were tumor size, number of tumors, cancer cell infiltration of the fibrous capsule of the tumor, portal involvement, and stage of the tumor, but the grade of anaplasia according to Edmondson-Steiner's classification and the severity of associated liver cirrhosis did not show a correlation with the incidence of recurrence. According to Akaike's Information Criteria (AIC), tumor number is useful for predicting early prognosis, and capsular infiltration is a good indicator of long-term survival. However, portal involvement gives much prognostic information throughout the entire postoperative period.

Adult↗
PubMed1992

TNM staging system.

Explore the source record for details and available documents.

Colorectal Neoplasms↗
PubMed1992

Histopathological prediction of liver metastasis after curative resection of colorectal cancer.

To estimate the risk of liver metastasis after curative resection of colorectal cancer, resected specimens from 290 patients (45 with metachronous liver metastasis) were examined and the relationships between 10 histopathological variables and liver metastasis were analysed using our application of the Akaike information criterion (AIC). Of the 10 variables examined, the depth of venous invasion (Vd) had the greatest prognostic value for metastasis, followed by the number of venous invasions, the number of lymphovascular invasions, lymph node metastasis and type of infiltration. The prediction of liver metastasis was further improved by combining Vd with lymphocyte infiltration, mucinous production, interstitial fibrosis or depth of penetration, although these four variables per se were minimally informative for metastasis. We conclude that the prediction of liver metastasis is best achieved by combining Vd with other variables. Our risk group classification, and the estimated probability of liver metastasis for each group, are shown.

Adenocarcinoma↗
PubMed1992

Coronary risk factors used to predict coronary artery disease by logistic regression analysis.

Risk factor analysis in coronary artery disease was conducted in 303 patients who underwent coronary arteriography to identify associations between personal characteristics and the prevalence of coronary heart disease. Age, sex, obesity, smoking, alcohol intake, hypertension, diabetes mellitus, serum uric acid, total cholesterol, LDL- and HDL-cholesterol, triglyceride, and atherogenic indices were statistically analyzed. All 13 variables were first compared between patients with positive and negative ergonovine tests. Only total cholesterol was significantly different, while significant differences in age, sex, history of diabetes, total cholesterol, LDL- and HDL-cholesterol, triglyceride and atherosclerotic indices were observed between patients with and without organic coronary artery stenosis. A multivariate analysis was performed, and the resulting equation was tested using the remaining patients. Logistic analysis of all 13 variables identified 5 (age, sex, diabetes mellitus, LDL- and HDL-cholesterol) which accounted for the differences between patients with and without significant coronary artery disease and that were validated in the test group. The sensitivity for prediction of coronary artery disease was 75.8%, specificity 68.5%, and predictive accuracy 71.5% in the test group. Thus, risk factor analysis appears to be very valuable in screening subjects with high-risk organic coronary stenosis and in optimizing the preventive and therapeutic modalities, but not in predicting vasospastic subjects.

Cholesterol↗
PubMed1992

Isolation of adult pig islet. In vitro assessment and xenotransplantation.

This study was conducted to develop an isolation method for adult pig islets and to investigate in vivo function after xenotransplantation as well as in vitro function of isolated islets. From the splenic portion of the glands (n = 20), 3277 +/- 645 islets per gram of pancreas were isolated and recovered by a five-step dextran discontinuous density gradient method. Purity of the final preparation obtained from 20 different consecutive pig pancreata was 80-90%. In vitro incubation study revealed a significant insulin release from isolated adult pig islets in response to glucose stimulation. In vitro perifusion study demonstrated a biphasic insulin response to glucose stimulation from isolated islets. Xenotransplantation of approx 2000 isolated adult pig islets into the portal vein of diabetic Wistar rats (n = 8) significantly reduced serum glucose levels from 431 +/- 24 mg/dL to 173 +/- 18 mg/dL 24 h after transplantation. This study provides a development of an isolation method for adult pig islets and demonstrates that isolated islets are viable and functioning both in vitro study and in vivo study of xenotransplantation.

Animals↗
PubMed1992

Experimental hybrid islet transplantation: application of polyvinyl alcohol membrane for entrapment of islets.

In this study, we first examined in vitro a polyvinyl alcohol membrane to be used to contain hybrid islet cells, and second we tested a bioartificial pancreas with entrapment of pancreatic islets in polyvinyl alcohol membrane in rats with experimentally induced diabetes. The permeability of the polyvinyl alcohol membrane to different substances was studied in a two-cell chamber system. Glucose, insulin, and nutrients passed through the membrane easily, whereas the passage of immunoglobulin G was completely prevented, indicating that this membrane could be effective in protecting the bioartificial pancreas from immunorejection. Approximately 2,000 islets collected from three Sprague-Dawley rats were enclosed in a mesh-reinforced polyvinyl alcohol tube and transplanted into the peritoneal cavity of six Wistar rats with streptozotocin-induced diabetes. Their nonfasting serum glucose levels were significantly decreased for at least 12 days. Six diabetic rats receiving intraperitoneal transplantation of free islets without the tube showed a slight but significant decrease in nonfasting serum glucose levels for only 3 days. One diabetic rat with transplantation of the bioartificial pancreas had a significant and sustained decrease in nonfasting glucose levels from pretransplanted levels of 440-500 mg/dl to a mean value of 162 +/- 13 mg/dl for over 3 months without immunosuppression. The bioartificial pancreas was then removed, and glucose levels gradually increased to over 500 mg/dl. The results of the present study suggest that a bioartificial pancreas with entrapment of islets in a polyvinyl alcohol membrane could be a promising therapeutic approach to diabetes mellitus.

Animals↗
PubMed1991

Systematic computer-aided search of optimal staging system for colorectal cancer.

Two hundred and ninety-eight patients with curatively resected colorectal cancer were classified into 12 categories according to the depth of tumour penetration (T1-T4), and lymph node status (N0-N2). Using a computer, these categories were grouped into 2-12 stages in every possible combination, so a total of 146,975 logical classifications were generated. The optimal model was selected for each group of classifications with equal stage number, thus giving the greatest prognostic information on 5-year survival according to the Akaike criterion. The results showed that (1) 13% of the total classifications, including 85% of the 3-stage classifications, were better than the Dukes system in predicting our patients' outcomes; (2) the T-level was a stage-determinant even more important than the N-level; and (3) major changes in prognosis occurred at more advanced stages than the classical "turning points". We conclude that in order to find an optimal staging of cancer, systematic computer-aided search through all the possible classifications is necessary, using the appropriate database.

Colorectal Neoplasms↗
PubMed1991

[Problems of clinical trials as viewed in the perspective of decision theory].

In this paper, the current clinical trial based on the Neyman-Pearson's principle of hypothesis testing is reviewed in the perspective of decision theory, its shortcomings are revealed and alternative methods proposed. In the current trial design, the alpha error is arbitrarily fixed at a level (e.g., 0.05), even lower than the beta error level (0.1 or 0.2). This results in failure with smaller trial size to identify the better treatment, dose-patient interaction, or optimal patient stratum for treatment. If on the other hand, the most harmless alpha error is ignored, the total number of patients expected to be cured can be substantially increased due to earlier identification of the better treatment. In case treatment, A has some disadvantages compared with B in terms of cost, toxicity etc., then the null hypothesis should be changed to "the cure rate of A is greater than that of B by delta", an adjustment for the disadvantages, which can be estimated by utility analysis. The loss to the society and target population may be further increased if improper regimen is provided including omission of the best treatment arm, suboptimal treatment intensity, selection of improper patient stratum, failure to individualize treatment plan (inflexible regimen). In order to maximize the benefit of our patients and society, radical changes of the current clinical trial design is needed using decision analytical approach.

Antineoplastic Agents↗
PubMed1990

Extranodal non-Hodgkin's lymphoma of the head and neck. A clinicopathologic study in the Kyoto-Nara area of Japan.

The clinicopathologic features of 114 Japanese patients with extranodal non-Hodgkin's lymphoma of the head and neck region were analyzed. The median age was 60.5 years and the male:female ratio was 1.5:1. The most common site of involvement was Waldeyer's ring, followed by the oral cavity, thyroid gland, paranasal sinuses, nasal cavity, and larynx. Seventy-five percent of the patients were in Stage I or Stage II at admission. Histologically, diffuse lymphoma accounted for 94% and follicular lymphoma for 6% of cases. The histologic grade according to the Working Formulation System of the National Cancer Institute was low in 11%, intermediate in 75%, and high in 14% of cases. Immunohistochemical study showed that the majority of the cases were of B-cell type and only 13 cases (11%) were of the T-cell type. Peripheral T-cell lymphomas (eight cases) mainly occurred in the nasopharynx and nasal cavity, whereas four of five thymic T-cell lymphomas were found in the palatine tonsil. The over-all 5-year survival rate was 54%, and the factors affecting survival were sex, histologic grade, T/B phenotype, clinical stage, and the site of initial presentation. Five-year survival with nasal cavity and Waldeyer's ring lymphoma was 24% and 46%, respectively. The poor prognosis of lymphomas at these sites might result from the predominance of T-cell lymphoma, the paucity of low grade lymphoma, and the relatively high incidence of cases that were in an advanced stage at presentation. In Stage II, patients treated with combined therapy tended to have a better 5-year survival rate than those treated with radiotherapy alone.

Adolescent↗
PubMed1990

[The preoperative and postoperative carcinoembryonic antigen test in the diagnosis, staging, and prognosis of gastric cancer. Tumor Marker Committee, Japanese Foundation for Multidisciplinary Treatment of Cancer].

Preoperative and postoperative carcinoembryonic antigen (CEA) levels were studied in 3,532 patients with Surgically treated gastric cancer in 52 institutions from 1980 to 1981. These patients had disease resectable with curative intent and were followed for a minimum of 5 years or until death. Among 2,749 Stage I cases, 33 had recurrence and proved to be histologically stage I. A pair matching case control study between these 33 cases and matched 33 stage I controls without recurrence proved that the preoperative CEA level was relatively higher in cases with recurrence (p = 0.079). In Stage II and III cases, an analysis of variance using a cut off level as a block factor was performed. Among 315 Stage II cases, preoperative CEA levels were significantly higher in cases with recurrence than in cases without recurrence. In 468 Stage III cases, no correlations between preoperative CEA levels and high risks of cancer recurrence were detected. In Stage I and Stage II cases, CEA levels significantly increased at the time of recurrence. In conclusion, preoperative high serum CEA levels might be considered one of the risk factors for recurrence of Stage I and II gastric cancers, and monitoring the postoperative CEA levels might be useful in early detection of recurrence.

Analysis of Variance↗
PubMed1990

[Large bowel cancer: prognostic factors, surgical treatments and their results].

Although the classification proposed by Dukes has been repeatedly modified, causing unnecessary confusion, his original concept remains unrefuted; cancer penetration through the bowel wall and lymph node metastasis are two major prognostic factors, of which nodal metastasis represents a more advanced stage. However, the results of our exhaustive computer analyses did not support this concept, and better classifications may be developed using our computer algorithm, enabling us to refine the indication for extensive surgery or limited resection. There are two trends of surgical treatment in Japan. One is an attempt to extend the area of resection including the paraaortic and parailiac nodes, and also iliac vessels. Patients treated by this method show a higher survival rate if compared with historical controls in Japan. However, extensive surgery of the rectum is associated with poor quality of life with bladder and anal dysfunctions as well as sexual impotence. The other trend is to limit the extent of resection and minimize the functional defect. The organs thus saved include the sphincter and autonomic nerves. The results are almost comparable with those of more radical surgery. With aggressive re-resection of recurrent tumors in the liver, lungs, lymph nodes and local areas, the number of long-term survivors is now increasing who would otherwise have died.

Colorectal Neoplasms↗