Japanese journal of clinical oncology
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The main physiologically active polyphenol in green tea extract is (-)-epigallocatechin gallate (EGCG). Green tea extract has an advantage over EGCG as a cancer chemopreventive agent for humans, as is apparent from the Japanese custom of injesting green tea on a daily basis. Green tea extract similarly inhibited protein kinase C activation by teleocidin, a tumor promoter, as did EGCG. ⋯ An experiment using the estrogen-dependent MCF-7 cell line showed the mechanisms of action of these compounds to be inhibiting the interaction of estrogen with its receptors. Considering our previous results of a single application of EGCG to mouse skin inhibiting the specific binding of 3H-12-0-tetradecanoylphorbol-13-acetate (3H-TPA) and 3H-okadaic acid, we postulated that EGCG and compounds in green tea extracts would block the interaction of tumor promoters, hormones and growth factors with their receptors: a kind of sealing effect. The sealing effect would account for reversible growth arrest, and may be induced by various kinds of compound.
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Jpn. J. Clin. Oncol. · Jun 1993
Case ReportsLaryngeal metastasis from a pulmonary papillary adenocarcinoma: a case report.
Metastases to the larynx from distant primaries are very rare. The present article reports a case of metastatic papillary adenocarcinoma of the larynx of lung origin. The patient was a 59-year-old female non-smoker, who had a history of adenocarcinoma of the right lung. ⋯ The tumor of the larynx was a papillary adenocarcinoma resembling the lung tumor, both demonstrating positive immunohistochemical staining for pulmonary surfactant apoprotein. The findings emphatically indicated the laryngeal tumor to be metastasis from the primary papillary adenocarcinoma of the lung. The present case report presents the clinical findings, course of disease and histopathological findings with brief reviews of the literature.
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Jpn. J. Clin. Oncol. · Oct 1992
Estimating a summarized odds ratio whilst eliminating publication bias in meta-analysis.
Publication bias is a recognized phenomenon, i.e. studies with statistically significant results are more likely to be published than those finding no difference between the groups studied. Summarized odds ratio calculated from odds ratios of published studies in a meta-analysis may be overestimated because of publication bias. This is a significant problem in research areas involving weak associations between causes and results. ⋯ The present study enables us to calculate the summarized odds ratio of hypothetical unpublished studies from odds ratios of published studies indirectly, employing a moment method by assuming the natural logarithm value of the odds ratio to be distributed normally. We can then estimate summarized odds ratio in all studies, which include not only those published but also those unpublished. When these studies are homogeneous in quality and their odds ratios homogeneous in quantity, the method can eliminate publication bias.
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Jpn. J. Clin. Oncol. · Sep 1989
Dealing with the proportional hazards assumption when using the proportional hazards model with a single independent variable.
In order to examine the proportional hazards assumption implicit in the proportional hazards model, three types of simulations were carried out on two groups of hypothetical survival data. Simulation 1 assumed that the hazard rate for one group was higher than that for the other group but that they were not proportional. Simulation 2 was an example of hazard rates crossing each other. ⋯ Although the increase in number of subjects was found to favor detections of violations of the proportional hazards assumption, cases such as those in Simulation 1 were considered acceptable for clinical use. Cases such as those in Simulation 2 were not suitable for the proportional hazards model. Simulation 3 suggested that cases with a substantial degree of unproportionality could be detected to violate the proportional hazards assumption, even when groups of 100 subjects each were involved in the analysis.
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Jpn. J. Clin. Oncol. · Jun 1988
Use of Broviac/Hickman catheter for long-term venous access in pediatric cancer patients.
Forty-two indwelling central venous catheters were inserted in 29 pediatric patients with malignant solid tumors. Indications included pre- and postoperative parenteral nutrition, intensive chemo-radiotherapy and bone marrow transplantation. Fifteen of the central venous catheters (15 patients) were Broviac/Hickman and remaining 27 catheters (14 patients) were traditional Silastic. ⋯ Overall complication rates, including infection, accidental removal, and occlusion of the catheter, were 9.6 per 1,000 Silastic use days and 0.35 per 1,000 Broviac use days. No deaths were related to catheter complications. For long-term angioaccess in pediatric cancer patient the Broviac catheter was demonstrated to have a lower complication rate than the traditional Silastic catheter.