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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 1,225 records · Page 68Linked to original sources

Follicle culture enhances fertilizability and cleavage of bovine oocytes matured in vitro.

The fertilization and cleavage of bovine oocytes matured by intra- or extra-follicular methods were investigated. Oocytes were fertilized in vitro or in the rabbit oviduct and cleavage was assessed after in vitro culture of in vitro fertilized oocytes and after in vivo culture (rabbit oviducts) of xenogenously fertilized oocytes. The effect of fertilization with fresh-diluted or frozen-thawed semen were also examined. The intra-follicular method did not increase the nuclear maturation rate as compared with the extra-follicular method (57.9 and 52.7%, respectively). However, the proportions of in vitro fertilized eggs (54.8%) and of cleaved eggs (two to eight cells; 34.6%) in the rabbit oviduct for 48 h after xenogenous fertilization were higher (P less than .025) in the intra-follicular oocytes than those of the extra-follicular oocytes (37.1 and 21.3%, respectively). It was also found that the use of fresh-diluted semen resulted in more cleaved eggs from the rabbit oviduct than the use of frozen-thawed semen (43.4 and 23.3% in the intra-follicular oocytes, P less than .025; 31.0 and 7.8% in the extra-follicular oocytes, P less than .05), while the appearance of cleaved eggs following in vitro fertilization was extremely low (0 to 6.6%). The present results demonstrated that the intra-follicular culture method of bovine oocytes provided a physiological environment for cytoplasmic maturation leading to higher fertilizability and development than the conventional in vitro culture of extra-follicular oocytes.

Animals↗

Thyroxine-induced molting and gonadal function of laying hens.

Twenty laying hens, 238 days of age, were divided into four groups which received daily intramuscular injections of L-thyroxine (T4) (0, 20, 100, or 500 micrograms/kg body weight per day) for 4 weeks. There was no change in body weight or egg production rate of the control (0 microgram T4) or of 20 and 100-micrograms T4 groups over time. Body weight and egg production of the 500 micrograms T4 group decreased markedly and molting started 10 days after T4 injection. Circulating iodothyronine (T4), triiodothyronine (T3), and reverse triiodothyronine (rT3) of the 500-micrograms T4 group increased markedly (30 to 150 times those of the control group) whereas serum luteinizing hormone and progesterone declined after one week and estradiol after two weeks. We concluded that a large dose of T4 (500 micrograms T4/kg, body weight per day) induced an increase in circulating iodothyronine levels, decreased secretion of gonadotropin and sex steroid hormones, and induced molting.

Animals↗

A sandwich enzyme immunoassay of an adenocarcinoma-associated antigen, YH206, in cancer sera.

A sandwich enzyme immunoassay was established to measure an adenocarcinoma-associated antigen (antigen YH206) detected by monoclonal antibody YH206. Levels of antigen YH206 exceeding the cut-off value (25 U/ml) were found in the following percentages of 163 patients with various cancers: stomach cancer 37.2%, colon cancer 14.8%, pancreas cancer 43.3%, common bile duct cancer 28.6%. In contrast, only one out of 33 (3.0%) healthy donors and 7 of 104 (6.7%) patients with benign diseases had slightly elevated levels of the antigen. As regards the relationship between antigen YH206 levels and clinical stages, abnormally high levels of the antigen were found in the following percentages of 29 patients with stomach cancer: stage I 16.7%, II 0%, III 42.9% and IV 54.5%. Serial monitoring of antigen YH206 in two patients with cancer revealed that the level of the antigen increased as the disease progressed. It was also found that perchloric acid treatment of serum might be useful to decrease any false-positive reactions.

Adenocarcinoma↗

Serological and immunohistochemical detection of a gastrointestinal cancer-associated asialoglycoprotein antigen of human with a murine monoclonal antibody.

A murine monoclonal antibody (mAb), NCC-AS 13 (IgM, kappa), was produced after immunization with ascites from a gastric cancer patient. In a sandwich enzyme immunoassay, NCC-AS 13 reacted with the sera from 32% of 58 gastric cancer patients, 44% of 9 hepatocellular cancer patients and 33% of 6 colorectal cancer patients. Immunohistological analysis showed NCC-AS 13 to react with approximately 90% of 51 gastric carcinomas, 12 out of 12 colon carcinomas and 3 out of 4 lung carcinomas. The NCC-AS 13 defined antigen was determined to be a carbohydrate without terminal sialic acid on macromolecular glycoproteins. This mAb NCC-AS 13, detecting a novel antigen associated with gastrointestinal cancers, may have potential uses for tumor immunoscintigraphy and for the therapy of gastric cancer patients.

Antibodies, Monoclonal↗

[The evaluation of chemotherapy of relapse in prostatic cancer with new response criteria].

Effect of chemotherapy for relapse of prostatic cancer was evaluated with new response criteria, in which four objective parameters including the prostate, bone metastasis, soft tissue metastasis and the serum acid phosphatase level estimated by radioimmunoassay or enzyme immunoassay were judged separately and then summarized to evaluate the response as complete response (CR), partial response (PR), stable and progressive disease (PD). Eighty-two patients were included in the study. Rate of PR and stable were 19% and 27%, respectively, and these two groups showed longer survival than those with PD. Evaluation of prostate and bone showed tendency to be discrepant with total judgement. Evaluation of soft tissues and prostatic acid phosphatase reflected the effect of chemotherapy. Chemotherapy often improved subjective symptoms but the effect did not parallel the total judgement in many cases. Factors influencing response of chemotherapy were mode of pretreatment, performance status, age, number of affected areas and clinical stage, but the grade at initial treatment was not correlated to response. The new criteria used in this study was valid for evaluation of response in prostatic cancer.

Acid Phosphatase↗

A new noninvasive quantitative assessment of cerebral blood flow using N-isopropyl-(iodine 123)p-iodoamphetamine.

The use of a nomogram is described as a new noninvasive quantitative assessment of cerebral blood flow using N-isopropyl-(123I)p-iodoamphetamine (IMP) and single-photon emission computed tomography. The nomogram was constructed from a computer analysis of the flow value relative to varying washout rate of brain activities between early and late tomographic images, and partition coefficient between brain tissue and blood. The validity of this method was evaluated in normal volunteers and in patients with cerebrovascular disorders by comparing the cortical flow values (Y) estimated from the IMP-nomogram with initial slope indices (X) by the 133Xe inhalation method. A significant correlation (N = 42, r = 0.88, P less than .001) was demonstrated between them, and the regression line was Y = 1.6X-7. A development and confirmation of this method made it possible to measure flow values noninvasively with the use of IMP.

Adult↗

[Analysis of tumor-associated antigen of the digestive tract by monoclonal antibody].

A sandwich enzyme immunoassay was established for measuring an adenocarcinoma-associated antigen (antigen YH206) detected by monoclonal antibody YH206. A level of antigen YH206 exceeding the cut-off value (25 U/ml) was found in the following proportions of 136 patients with digestive organ cancers: stomach cancer 37.2%, colon cancer 14.8%, pancreas cancer 43.3%, common bile duct cancer 28.6%. In contrast, only one out of 33 (3.0%) healthy donors and 7 of 104 (6.7%) patients with benign diseases had slightly elevated levels of the antigen. It was also found that perchloric acid treatment of serum might be useful for decreasing any false-positive reactions. The YH206 antigen was then purified by affinity chromatography using MoAb YH206-coupled CNBr-Sepharose. This antigen was not recognized by MoAb CA19-9. Studies on the chemical nature of the antigenic determinant of the YH206 antigen suggested that MoAb YH206 recognized a unique carbohydrate determinant of a novel adenocarcinoma-associated antigen in the sera of cancer patients. In addition, a new monoclonal antibody BM2 (IgM) was established using YH206 antigen as an immunogen. This antibody might be more useful than antibody YH206 in the detection of circulating antigen in the sera of patients with digestive tract cancer.

Adenocarcinoma↗