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Biomedical subjects

T Kameda

Publications and source records attributed to T Kameda.

At least 127 records · Page 7Linked to original sources
PubMed1987

Expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by chemical carcinogens.

The expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or 1, 2-dimethylhydrazine (DMH) was studied by Western blotting and immunohistochemistry using anti-Ha-ras p 21 oncoprotein antibody. In Western blotting, high levels of c-Ha-ras p 21 were found in serially transplantable rat duodenal carcinomas induced by MNNG and rat colon carcinomas induced by DMH. Immunohistochemically, c-Ha-ras p 21 immunoreactivity was detected in 3 (16.7%) of 17 MNNG-induced stomach carcinomas and in 21 (63.6%) of 33 DMH-induced colon carcinomas, respectively. In the colon carcinomas, c-Ha-ras p 21 immunoreactivity in deeply invasive tumors was stronger than that in superficially invasive tumors and was expressed in all subserosal tumors. Moreover, all of the metastatic colon carcinomas had c-Ha-ras p 21 immunoreactive tumor cells. These findings suggest that c-Ha-ras p 21 expression plays an important role in tumor proliferation, invasion and metastasis of DMH-induced colon carcinoma.

Adenocarcinoma↗
PubMed1987

Effect of a soluble factor secreted from cultured human trophoblast cells on in vitro lymphocyte reactions.

The immunoregulatory role of trophoblast cells in cell-mediated immunity was investigated. Trophoblast cells were obtained from 8-10-week human placentae by treatment with collagenase followed by differential centrifugation. The cells were cultured for 48 hr, and the culture supernatant was examined for immunosuppressive activity in vitro. The supernatant when added to cultures of peripheral blood lymphocytes from healthy donors suppressed both their reactivity to different lectins (PHA and PWM) and their activity in one-way mixed lymphocyte reaction. The degree of suppression was dose-dependent. Furthermore, the supernatant was able to reduce the natural killer cell activity against K562 target cells. On the other hand, the supernatant had no inhibitory effect on the effector phase of lymphocyte-mediated cytotoxicity activity against tumor cell lines RPMI 8866 and Daudi. In all cases, the suppression observed was not due to lymphocytotoxicity or tumor cell mortality. The results indicate that trophoblast cells release a soluble suppressive factor that is a potent inhibitor of cell-mediated immunity.

Cytotoxicity, Immunologic↗
PubMed1987

[ELISA for antisperm antibodies in unexplained infertile women].

It is commonly believed that autoimmune or isoimmune responses to human sperm antigens are associated with human infertility. We examined an enzyme linked immunosorbent assay (ELISA) kit used in the detection of antisperm antibodies in the sera of women with unexplained infertility. 1) For the ELISA assay, an absorbance at 405nm greater than 0.300 was considered positive. Of the 83 sera of infertile women studied, 20(24.1%) were positive. This value was significantly higher than that of the control group: 10% of pregnant women, 11.1% of unmarried women and 10% of healthy men (p less than 0.05). 2) The results obtained with ELISA were compared with those of the sperm immobilization test. Comparison of the results of ELISA with those of the sperm immobilization test indicated that these methods detect a different, though often overlapping, spectrum of antibody activity. 3) The results obtained with ELISA did not always correlate with those of the Huhner test. However the ELISA method may be useful in the clinical screening of antisperm antibodies because of its simplicity and rapidity.

Adult↗
PubMed1987

[A case of sweat gland carcinoma arising in a mature cystic teratoma of the ovary].

A case of sweat gland carcinoma arising in a mature cystic teratoma in a 63-year-old woman is reported. The patient was admitted with the complaint of a lower abdominal pain. Under the diagnosis of a mature cystic teratoma of the right ovary, the tumor was removed. Histologically, adenocarcinoma was found in the wall of the mature cystic teratoma. A part of the tumor showed a differentiation of the secretory portion and duct of the sweat gland. Histochemically, sialic acid containing mucoprotein was defected. Electron microscopically, the tumor cells were found to have secretory granules and intracytoplasmic canaliculi. Therefore, the tumor was diagnosed as a sweat gland carcinoma arising from a mature cystic teratoma.

Adenocarcinoma↗
PubMed1986

[Stereotype-based expectancy and social judgment: rethinking from a Bayesian perspective].

To examine effect of prior stereotypical expectancy on social judgment from a Bayesian perspective, undergraduate subjects (N = 204) were asked to infer a target person's attitude toward an atomic power problem. Half of them were told in advance that he was a member of Liberal Democratic Party (pro-expectancy condition), and the other half were told that he was a member of Japanese Socialist Party (con-expectancy condition). Then subjects were given a series of his previous relevant utterances, which had either high or low diagnostic values for the inference of his attitude. "Labeling effect" occurred. That is, despite being given identical utterances, subjects given L.D.P. label estimated the target's attitude to be more favorable toward the atomic power than subjects given J.S.P. label. This effect emerged mainly when subjects were given low diagnostic utterances. Subjects given high diagnostic utterances inadequately underused the base-rate information (prior expectancy) compared with the Bayesian normative value. Utterances congruent with prior expectancy were better recalled than utterances incongruent with prior expectancy.

Adult↗
PubMed1983

Correlation among water content, left ventricular function, coronary blood flow, and myocardial metabolism after hypothermic ischemic cardiac arrest.

Subendocardial ischemia is a common cause of death following ischemic cardiac arrest. We studied relationships among myocardial water content (WC), left ventricular function, coronary blood flow, and myocardial metabolism following ischemic cardiac arrest. Under cardiopulmonary bypass with hypothermia, 120 min of aortic occlusion was employed, and myocardial temperature was kept around 20 degrees C in 10 mongrel dogs. Left ventricular function (peak LVP, max dp/dt, LVEDP, LVSWI), coronary blood flow, myocardial enzymes (m-GOT, total CPK, MB-CPK), myocardial ATP and creatine phosphate (CP), and WC of the subendocardium of the left ventricle were measured. Data were obtained in the control state and immediately and 30 and 60 min after aortic unclamping. Significant negative correlations were obtained between WC and max dp/dt (r = -0.8384), coronary blood flow (r = -0.9928), ATP (r = -0.7038), and CP (r = -0.7835). Significant positive correlations were obtained between WC and LVEDP (r = 0.7525), m-GOT (r = 0.7638), and total CPK (r = 0.7079). These data suggest that myocardial edema results in depression of left ventricular function and metabolism.

Adenosine Triphosphate↗
PubMed1982

Studies on the significance of serum mitochondrial aspartate aminotransferase activity following ischemic cardiac arrest.

Aspartate aminotransferase (EC 2.6.1.1:AST) is known to have two isoenzymes, one associated with the cytoplasm (c-AST) and the other with the mitochondria (m-AST). We studied the relationships of m-AST activity in the coronary sinus blood to left ventricular function, coronary blood flow, water content and high-energy phosphate stores of the left ventricle following hypothermic ischemic cardiac arrest. Under cardiopulmonary bypass with hypothermia of 20 degrees C of myocardial temperature, 120 min of aortic occlusion was employed in 15 mongrel dogs. Left ventricular function (peak left ventricular pressure, left ventricular end-diastolic pressure, max dp/dt, cardiac index, left ventricular stroke work index), coronary blood flow, myocardial oxygen consumption, myocardial enzyme activity (m-AST, CK-MB), myocardial water content and high-energy phosphate stores (adenosine triphosphate, creatine phosphate) of the subendocardium of the left ventricle were measured. Data was obtained in the control state, and after 0, 30 and 60 min of reperfusion. Significant negative correlations were obtained between m-AST activity and peak left ventricular pressure (r = -0.81, p less than 0.001), max dp/dt (r = -0.83, p less than 0.001), cardiac product (r = -0.73, p less than 0.01), coronary blood flow (r = -0.59, p less than 0.05), adenosine triphosphate level (r = 0.72, p less than 0.01) and creatine phosphate level (r = -0.72, p less than 0.02) after 60 min of reperfusion. Significant positive correlations were obtained between m-AST activity and left ventricular end-diastolic pressure (r=0.75, p less than 0.01) and water content (r = 0.78, p less than 0.01) after 60 min of reperfusion. These results led to the assumption that serum m-AST activity in the coronary venous blood is a useful index to evaluate the degree of myocardial injury.

Adenosine Triphosphate↗
PubMed1982

The optimal flow rate during reperfusion after hypothermic ischemic arrest.

This experiment was designed to determine the optimal flow rate during early reperfusion after ischemic arrest for one hour at 28 degrees C of myocardial temperature, assessed by cardiac function, biochemistry and fine structure of the left ventricle. Under cardiopulmonary bypass (CPB) at a flow rate of 80 ml/kg/min, the ascending aorta was clamped for one hour at 28 degrees C of myocardial temperature in 19 mongrel dogs. After the aorta was declamped, the perfusion pressure was maintained at 50 mmHg and dogs were divided into 3 groups by flow rate of 50 (Group A), 80 (Group B) and 150 ml/kg/min (Group C) for 15 min of reperfusion. The left ventricular function was measured and calculated before the institution of CPB and 30 and 60 min after the declamping of the aorta. Myocardial isoenzymes (m-GOT, MB-CPK) in the coronary sinus venous blood were measured. Myocardial adenosine triphosphate (ATP), creatine phosphate (CP) and water content were measured by the samples of the epicardial and endocardial layers of the left ventricle and the ventricular septum at the end of experiment. The subendocardium of the left ventricle was examined by electron microscopy. Mortality rates were 1/6 (16.7%) in Group A, 2/7 (28.6%) in Group B and 4/6 (66.7%) in Group C. The myocardial water content was the lowest, and ATP was significantly higher in Group A compared to others. Left ventricular endodiastolic pressure was the lowest and the ultrastructure was well maintained in Group A. These data suggest that a high flow rate is detrimental to myocardial recovery during early reperfusion, and the optimal flow rate during early reperfusion after ischemic arrest (60 min, 28 degrees C) appears to be 50 ml/kg/min.

Adenosine Triphosphate↗
PubMed1980

Additive protection of aprotinin, protease inhibitor to cold cardioplegia from ischemic myocarium.

Protective action of aprotinin froom ischemic myocardial damage was evaluated in 9 patients compared to non-treated 18 patients, who underwent open heart surgery (22 ACB, 3 AVR and 2 MVR) with respect to the alterations of beta-glucronidase, acid-phosphatase, MB-CPK and m-GOT. Cold cardioplegia with glucose-insulin-potassium solution was used in this investigation. Average arrest time was 78.6 +/- 4.9 minutes associated with hypothermia between 25 and 28 degrees C in rectal temperature. Aprotinin was administered in 9 patients intravenously with 5,000 KIU/Kg 30 minutes prior to CPB and then 5,000 KIU/Kg in the prime solution. Activity of beta-glucronidase was significantly suppressed in the aprotinin-treated group compared to the non-treated group following cardioplegia and in the reperfusion period up to 6 hours, however, acid-phosphatase failed to demonstrate significant difference among two groups. Serum MB-CPK and m-GOT levels in the aprotinin-treated group did not elevate the beginning of reperfusion following cardioplegia. These data suggest that aprotinin add myocardial protection to cold cardioplegia.

Acid Phosphatase↗
PubMed1977

[The dental soldering by means of high frequency induction heating (author's transl)].

The authors examined the methods of high frequency induction soldering, especially Loop-method, other than the gas flame soldering which was known generally. The details which was done are: (1) about the form of induction coil, and the relative places of the coil and restrative appliance, and some supplementary appliances of them. (2) about strength of soldered joints of Co-Cr wire using silver solder and Pd-solder, and observation on the corrosion of soldered-joints by the scanning electron-microscope. (3) about the comparison of the characteristics of Co-Cr wire by means of high-frequency induction heating and gas-flame one. (4) about the examples of soldering of porcelain crown-bridge and clasp wire attached on the dental cast, and possibility of soldering techniques of them on the dental cast. The authors found that the high frequency induction method was preeminent from the other method on the point of (a) the characteristic of heated wire, (b) the strength of soldered joints, (c) the easiness of operating of them, and (d) the possibility of soldering using the high-melting point of Pd-solder, and the soldering of them on the dental cast. Therefore we can enough respect the application on the dental area of this apparatus and this techniques of the high-frequency induction soldering.

Chromium Alloys↗