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K Imai

Publications and source records attributed to K Imai.

At least 1,333 records · Page 74Linked to original sources
PubMed1984

Stimulation of the release of lysosomal and nonlysosomal granular enzymes from macrophages treated with monensin.

Mouse peritoneal macrophages that had been treated with a monovalent carboxylic ionophore, monensin, selectively secreted lysosomal and nonlysosomal granular enzymes into the medium. When macrophages were incubated with 1 to 10 microM monensin, the release of beta-glucuronidase, beta-hexosaminidase and beta-galactosidase was stimulated time and does dependently. Neither the beta-glucosidase nor acid phosphatase, enzymes bound to the lysosomal membranes, however, were released by monensin. Neutral alpha-glucosidase, shown recently to be localized in nonlysosomal granules of macrophages (15), was released by monensin at concentrations lower than those required for lysosomal enzyme release. Increased release of lysosomal enzymes also took place in a manner similar to that seen with monensin-treated macrophages after treatment of macrophages with weak bases, chloroquine and ammonium chloride. Neutral alpha-glucosidase, however, was not released when chloroquine was present in concentrations that stimulated the release of lysosomal enzymes. The UDP-galactosyltransferase activity of the Golgi apparatus in the macrophages markedly decreased after treatment with low concentration of monensin.

Acid Phosphatase↗
PubMed1984

Time of follicular transformation to the rapid growth phase in relation to the ovulatory cycle of laying hens.

To demonstrate time of transformation of ovarian follicles from the resting stage to the rapid growth phase, Sudan black in ethanol was intravenously injected into laying hens, and 4 hr later Sudan red in water was injected into the same hens; the hens were killed 4 hr after the last injection for observation of the follicles. Injections were made at various times during an ovulatory cycle. In an additional experiment, hourly yolk deposition in the dark period (1900 to 0500 hr) was compared with that in the light period. Follicular transformation occurred at a high frequency within the period of 8 to 14 hr after ovulation. This period corresponded to the time between 1700 and 2400 hr. Hourly yolk deposition in the dark period was higher than that in the light period.

Animals↗
PubMed1984

The relationships of clutch length and egg position on ovarian follicular growth in laying hens.

To analyze characteristics of follicular rapid growth patterns in relation to clutch length and egg position in various clutch lengths, Sudan black and red were alternately injected intravenously into laying hens. The average growth period tended to decrease as clutch size increased, and this was accompanied by an increase in growth rate. The number of growing follicles and the total amount of daily yolk deposition in layers with short clutches were less than in layers exhibiting long clutches. The growth period tended to decrease as egg position advanced in clutches of 2 to 6 eggs. Follicular volume at ovulation also tended to be less in terminal (Ct) follicles in clutches of 2 to 5 eggs. Follicular growth rate was generaly reduced in the first egg of a clutch (Cl) and increased in the Ct follicles. Comparison of growth patterns between Ct and Cl follicles led to the detection of two growth patterns. In the first pattern, the growth period of the Ct follicle was equal to that of the Cl follicle and a one day skip was found between the transformation days of the two follicles; in the second pattern, Ct and Cl follicles entered into the rapid growth phase on consecutive days, but the Cl follicle took one day longer than the Ct follicle to reach ovulation.

Animals↗
PubMed1984

Immunologic characterization and molecular profile of carcinoembryonic antigen detected by monoclonal antibodies.

Four distinct monoclonal antibodies, which reacted with CEA preparations but not with nonspecific cross-reacting antigen or with nonspecific cross-reacting antigen 2, were established. Except for monoclonal antibody AS001 , all of these monoclonal antibodies immunoprecipitated molecular forms of 200K and 180K daltons that are not bridged by disulfide bonds. Immunodepletion experiments and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed that these monoclonal antibodies recognized the same antigenic structure when 125I-CEA preparation was used. Monoclonal antibody AS001 is of particular interest, because this antibody reacted only with a 200K dalton molecule which is a part of the molecules recognized by the other three monoclonal antibodies. The rosette inhibition assay and the immunoprecipitation experiments suggest that each monoclonal antibody recognizes a different antigenic determinant. The antigenic determinants recognized by monoclonal antibodies YK013 and AS001 may be peptides in nature, whereas the determinants recognized by antibodies YK024 or AS005 might be carbohydrate. The radioimmunoassay with monoclonal antibody AS001 was established, and the results clearly indicate that the incidence of positivity for the sera from digestive tract cancer patients and from lung cancer patients obtained by monoclonal antibody AS001 was higher than that obtained by the polyclonal antibody. Monoclonal antibody AS001 was able to detect the corresponding antigen in the sera, which the polyclonal antibody failed to detect. This study therefore suggests that monoclonal antibodies may enhance and improve the diagnostic value in cancer patients with undetectable or lower CEA levels detected by conventional anti-CEA antibodies.

Animals↗
PubMed1984

Immunohistochemical distribution of the antigenic determinants detected by monoclonal antibodies to carcinoembryonic antigen.

By using four distinct monoclonal antibodies to CEA, the molecular profile of which was clarified in our accompanying companion paper, immunohistochemical distribution of the antigenic determinants on both cancerous and noncancerous tissues as well as fetal tissues was studied with the use of the immunoperoxidase method. All of the monoclonal antibodies recognize different antigenic determinants on the tissue section. None of the antibodies stained granulocytes in the peripheral blood or in the normal liver tissues tested. Three of our monoclonal antibodies stained columnar epithelial cells in morphologically normal colonic mucosa; however, monoclonal antibody YK024 did not stain them. This antibody was also found to be unreactive with intestinal metaplasia lesions of the stomach, but reacted with a 16-wk-old fetal stomach as well as with cancerous parts of the colon and of the stomach. Moreover, it was found that this monoclonal antibody mainly reacted with moderately or poorly differentiated adenocarcinoma lesions of the colon and the stomach. Periodic acid treatment in this study, together with trypsin treatment on the antigen as described in our accompanying companion paper, may suggest that this antibody recognizes the carbohydrate antigenic determinant in nature.

Adenocarcinoma↗
PubMed1984

[Studies on serum CEA levels measured by enzyme immunoassay using monoclonal CEA-antibodies].

A double determinant enzyme immunoassay (EIA) using two monoclonal antibodies against CEA was established in the Abott laboratory. Serum CEA levels from patients with various cancers and benign diseases were measured using this EIA in comparison with the results obtained by radioimmunoassay (RIA) using polyclonal antibody against CEA. A significant correlation was noted between the values measured by the two methods. When serum CEA levels were more than 100 ng/ml, the values for EIA were found to be higher than those for RIA. However, this EIA was judged to be useful for monitoring cancer patients.

Antibodies, Monoclonal↗
PubMed1984

[Estracyt (estradiol-nitrogen mustard complex)--estramustine binding protein and its specificity].

Estracyt (estramustine phosphate) is a nitrogen mustard derivative of estradiol-17 beta which is rapidly dephosphorylated to yield estramustine. Estramustine is metabolized to estromustine mainly in the liver. Both estramustine and estromustine are retained in rat prostate with a high degree of specificity. This retention is due to the binding of estramustine and/or estromustine to a protein called EMBP (estramustine binding protein). When estimated by HPLC, the molecular weights of these estramustine binding components in rat prostate are 45,000-50,000 and 25,000-30,000, respectively. HPLC and glycerol density gradient analysis clearly demonstrated the occurrence of EMBP in a cytosol preparation from human prostatic cancer tissue. When estimated by HPLC, the molecular weights of estramustine binding components are 45,000 and 25,000 daltons, respectively. In addition, results of effectiveness of Estracyt studied under a cooperative research group in Japan, are reported in this paper. Effectiveness was evaluated at 3 months of the treatment on 121 patients with untreated prostatic cancer (Study I) and 95 patients with reactivated cancer (Study II), at 12 months of the treatment on 68 patients in Study I and 85 patients in Study II, and at 24 months on 37 patients in Study I and 23 patients in Study II. At 3 months of the treatment, Estracyt was effective in 89% of untreated prostatic cancers, and 38% of reactivated prostatic cancers. At 24 months of the treatment, this drug was effective in 65% of untreated prostatic cancers and 30% of reactivated ones. Estracyt is especially recommended as a first-choice drug for both the untreated patients with poorly differentiated adenocarcinoma and reactivated cancer.

Animals↗
PubMed1984

[Low-dose methotrexate and sequential 5-FU treatment in advanced gastric cancer].

Combination chemotherapy of low-dose methotrexate and sequential 5-FU was given to 16 patients with advanced gastric cancer. Treatment regimen : methotrexate 30 mg/m2 followed 3 hours later with 5-FU, 750 mg and 24 hours later with leucovorin 30 mg/m2. Each drug was administered as a bolus. Treatment was repeated weekly. The median ECOG PS was 3 (range 2-4) and median age was 55.1 years (range 28-87). Of these 16 patients who were evaluated, four had PR, and 5 had MR, giving a response rate of 25%. Of the 7 patients who had been previously treated with a combination of chemotherapy including 5-FU, the figures were 2 PR and 3 MR. This regimen has been well tolerated by the patients. No patient had a WBC nadir of less than 2000 cells/mm3, and no patient had a platelet count nadir of less than one hundred thousand platelets/mm3. No other toxicity was detected.

Adenocarcinoma↗