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Biomedical subjects

Y Kitsukawa

Publications and source records attributed to Y Kitsukawa.

29 records · Page 2Linked to original sources

[Studies on biodegradable microspheres containing mitomycin C].

For the purpose of enhancing antitumor effects, we prepared heated albumin microspheres containing an antitumor drug, mitomycin C. The biodegradable MMC microspheres which have an average diameter of 45 +/- 8 mum contain approximately 10% of MMC and release in vitro approximately 20% of the MMC over 3-day period. The microspheres were injected into albino rabbit femoral artery of the hind leg into which a VX-2 tumor had been implanted. Peripheral blood levels of MMC were reduced as compared to the conventional MMC group, within 60 minutes after injection. Subsequently in the MMC-microsphere administered rabbits, the level was higher than in the conventional MMC administered group. The survival of VX-2 tumor-bearing rabbits prolonged markedly with MMC microspheres.

Animals↗

[Immunologic studies on the patients with gastrointestinal cancer--with particular reference to correlation between T lymphocyte and macrophage].

Correlation of monocyte with T lymphocyte or IgG-FcR+ T lymphocyte was studied in 57 gastrointestinal cancer patients and 24 healthy volunteers as control. In 24 volunteers, no correlation was found between them. Forty gastrointestinal cancer patients with curative tumor showed pre-and postoperatively a close correlation between monocyte and T lymphocyte, but there was little correlation, both pre-and postoperatively, between monocyte and IgG-FcR+ T lymphocyte. Seventeen patients with recurrent and/or inoperable gastrointestinal cancer, had a reverse correlation of monocyte with IgG-Fc R+T lymphocyte. It was suggested from these data that mononuclear phagocyte system (monocyte), which fulfils its function as an antigen presentation, has an intimate relationship, both directly and indirectly, to T lymphocyte.

Adult↗

Further investigations of immunoreactive carcinoembryonic antigen (CEA) in colorectal cancer patients--with particular emphasis on the correlation between immunoreactive CEA levels in tissue, feces and blood.

Immunoreactive carcinoembryonic antigen (IR-CEA) levels in colorectal cancer and mucosal tissues, feces and blood were measured in 14 colorectal cancer patients to study the correlation. IR-CEA levels in colorectal cancer tissues were about 30 times higher than those in colonic mucosal tissues. The correlation coefficient between IR-CEA levels in the tumor tissue and serum was 0.654 (p less than 0.02). We assumed that the total tumor IR-CEA levels were the product of the tumor IR-CEA level, by the estimated tumor weight. The correlation coefficient between the serum IR-CEA level and total tumor IR-CEA level was 0.750 (p less than 0.001). When the patients were divided into two groups with more and less a total tumor IR-CEA level of 65,000 ng, respectively, the statistical difference in serum IR-CEA levels was p less than 0.001. The differences in fecal IR-CEA levels between these two groups, however, are statistically insignificant (p less than 0.3). We assumed that there was a positive correlation between the IR-CEA levels in blood and tumor from the consideration that circulating IR-CEA originates from the metabolic imbalance of its production in colorectal cancer tissues over its degradation in the liver. Moreover, it is essential to consider that the fecal IR-CEA levels may be influenced by the following three factors: the intraluminal direct release of CEA from tumor, no degradation process of CEA in the gut lumen, and the intraluminal transport rate of colonic contents.

Aged↗

Comparative efficacy of antitumor treatment for liver metastases from colorectal cancer.

A retrospective study of 37 colorectal cancer patients with synchronous liver metastases was made. Of these patents, 6 who had undergone primary tumor removal were treated with considerable success by hepatic arterial infusion of 5-FU and mitomycin C. Ten patients who underwent primary tumor excision were treated by oral chemotherapy using fluorinated pyrimidines. These patients survived about 23 months. On the other hand, 12 patients after primary tumor removal without cancer chemotherapy survived for about 10 months. Six patients without antitumor treatment for both primary tumor and hepatic metastasis survived about 5.2 months. The overall results of this study suggest that intrahepatic arterial infusion is of practical importance for hepatic metastases from colorectal cancer and that oral chemotherapy is indeed effective for selected patients.

Adult↗

In vitro sensitivity test of stomach cancer tissues by the use of metal grid method.

Ninety-nine specimens obtained from 53 patients with stomach cancer were cultured for about 3 days by means of the stainless steel grid method. In vitro effects of antitumor drugs on the cancer cells were evaluated autoradiographically or biochemically using a liquid scintillation counter to measure the uptake of 3H-thymidine. The radioactivity of the labeled tumor cells of both control fragments and fragments affected by drugs varied greatly among individual tumors. Therefore, the in vitro efficacy of antitumor drugs was represented as a comparison with that of control fragments. Positive correlation between in vitro tests and the clinical effects of antitumor drugs was observed in the specimens of 18 cases.

Antineoplastic Agents↗

Immunoreactive carcinoembryonic antigen [CEA] levels in feces from colorectal cancer patients.

Immunoreactive CEA (IR-CEA) in feces or sera from 20 volunteers and 20 patients with colorectal cancer were measured before and at various intervals after surgery by a radioimmunoassay utilizing a "one step sandwich method." Elevated fecal IR-CEA level was observed in 17 of 20 patients with colorectal cancer; elevated serum CEA levels were observed in only 7 of all patients. There could not be found any correlation between fecal IR-CEA levels and Dukes' classification; there was but a little correlation between serum and fecal IR-CEA levels. In 8 of 14 patients treated by surgery, fecal IR-CEA levels obviously dropped, but in 2 patients with hepatic metastasis they were found rising in spite of colon tumor removal. It was speculated from these data that high values of fecal CEA depend on mass production of CEA by cancer cells. From these observations, it appears that fecal IR-CEA level presents a more ideal diagnostic competency in colorectal cancer than serum CEA level.

Carcinoembryonic Antigen↗

Stimulation of protein, RNA, and nucleotide synthesis in lymphocytes after abdominal surgery is not affected by postoperative amino acid supply.

The effects of abdominal surgery on protein, RNA, and de novo purine nucleotide synthesis in lymphocytes, and modification of these changes by postoperative amino acid supply, were investigated in 24 patients undergoing cholecystectomy (n = 12) or removal of gastric cancer (n = 12). Mono-nuclear cells were isolated from the peripheral venous blood and incubated with radioactive tracers in vitro. Protein and RNA synthesis, as measured using [14C] glycine and [3H]uridine, respectively, increased postoperatively. Nucleotide synthesis determined by the incorporation of radioactivity from [14C] glycine into nucleotides increased simultaneously. The concentration of 5-phosphoribosyl 1-pyrophosphate (PRPP) estimated by the incorporation of [14C]adenine into nucleotides also increased. These changes were greater and of longer duration in patients with cancer operation than in those with cholecystectomy. In neither case were they affected by the amount of amino acid intake, or increases in energy intake. These results suggest that abdominal surgery stimulates protein and ribonucleic acid (RNA) synthesis in lymphocytes. Increased RNA synthesis may be ensured by increased synthesis of nucleotides, and increased PRPP concentrations appear to regulate the rate of nucleotide synthesis. The responses are apparently dependent upon the severity of surgery, but unrelated to the amount of amino acid supplied postoperatively.

Adult↗