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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 1,261 records · Page 70Linked to original sources
PubMed1986

Improved method for purification of Xenopus laevis vitellogenin and demonstration of cross-reactivity among wide-range species by radioimmunoassay.

This study was performed to improve the purification of Xenopus vitellogenin and establish the radioimmunoassay. The procedure of purification consisted of ammonium precipitation, DEAE-Sephadex chromatography and Sephadex G-200 gel chromatography. Using this procedure, 934 mg vitellogenin was purified from 49 ml of estradiol treated female Xenopus plasma (about 19 mg/ml). Vitellogenins purified from male and female plasma after a single injection of estradiol showed good correspondence in electrophoretic patterns and amino acid compositions, indicating that vitellogenin synthesis in the male occurs in four different genes as in the female. The radioimmunoassay for vitellogenin was established using an antibody in the plasma obtained from rabbits injected with purified Xenopus female vitellogenin. The titer was 20,000 times dilution of the plasma, and the minimum detectable amount of vitellogenin was 0.1 microgram. The cross-reactivity of this antibody with newt vitellogenin was about 65% and that of chick 6%. The cross-reaction was also observed in female bullfrog plasma. Vitellogenin content was increased gradually during the first 6 days after injection of estradiol in female and the elevated level of vitellogenin dropped afterward.

Amino Acids↗
PubMed1986

Immunohistochemical analysis of human adenocarcinoma-associated antigen YH206 detected by a monoclonal antibody.

A monoclonal antibody YH206 (IgM, kappa) was prepared using human lung adenocarcinoma A549 cell line as an immunogen. The histological distribution of antigenic determinant of the YH206 antigen was highly restricted to adenocarcinomas of various organs including the lung, the pancreas and the stomach, but it did not react with 10 cases of colonic adenocarcinomas by the immunoperoxidase technique. It did not stain non-cancerous tissues of 16 different organs, except for the renal tubules and for the secreting glands of the pancreas with which the antibody faintly reacts. It did not react with either granulocytes, lymphocytes or red blood cells. Positive staining was observed in various fetal tissues. Periodic acid and neuraminidase treatments on tissue sections suggested that the chemical nature of the antigenic determinant of YH206 antigen was carbohydrate in nature which might be masked by sialic acids.

Adenocarcinoma↗
PubMed1986

Small cell undifferentiated carcinoma of the uterine cervix: histology, ultrastructure, and immunohistochemistry of two cases.

Two clinical stage IB small cell undifferentiated carcinomas (SCUC) of the cervix were studied by light and electron microscopy and immunohistochemistry. Both cases occurred in women aged less than 31 years. Despite radical hysterectomy and external pelvic radiotherapy, both patients died of recurrent disease within 14 months after initial therapy. The tumors consisted of sheets of closely packed, uniform small, round to oval cells with hyperchromatic nuclei and scant indistinct cytoplasm. One case was associated with cervical squamous cell carcinoma. The neoplastic cells had few organelles and desmosome-like junctions and lacked mucinous or neurosecretory granules or tonofilaments. Immunohistochemistry failed to reveal S-100, CEA, neuropeptides or neuron-specific enolase. SCUC probably arises either from basal cells of the cervical squamous epithelium, or gland cells of the endocervical epithelium, or still from subcolumnar endocervical reserve cells. Based on ultrastructure and immunohistochemistry, SCUC seems to represent the undifferentiated variant of small cell neuroendocrine tumors of the cervix.

Adult↗
PubMed1986

Effects of dietary level of protein on the maintenance energy requirement and net energetic efficiency for growth of post-weaning rats.

The effects of dietary protein on the maintenance energy requirement (MEm) and net utilization efficiency of metabolizable energy for growth (MEg) were investigated by regression analysis of energy balance with various energy intakes. Weanling rats of the Wistar strain, weighing about 85 g, were given a diet containing 0 to 70% casein freely or in restricted amounts (equivalent to two-thirds or one-third of the intake of the ad libitum group) for 5 days. The MEm was fairly constant in rats given 10 to 50% casein diets, being about 29 kcal/100 g BW/day, but increased at higher or lower dietary protein levels, indicating inefficient energy utilization in protein-malnourished animals. From the slope of the regression line between energy balance and metabolizable energy intake, the net energetic efficiencies for growth were estimated as 68, 71, 74, 77, 82, 83, 80, 78, 77 and 74% with 0, 3, 6, 10, 20, 30, 40, 50, 60 and 70% casein diets, respectively. Weanling rats fed 20 to 30% casein diets utilized the dietary energy for growth most efficiently. At protein levels higher or lower than 20 to 30%, the efficiency was less, showing that MEg utilization depended on dietary protein. The energy necessary for 1 g body weight gain was 2.6 kcal in rats receiving 30% casein diet, but increased with an increase or decrease in the protein level. These data on the food efficiency, MEm, the net efficiency of MEg and the energy necessary for 1 g weight gain show that dietary protein affects energy utilization and that protein-malnourished animals use energy inefficiently.

Animals↗
PubMed1986

Maintenance energy requirement in pregnant rats and net energetic efficiency for fetal growth during late pregnancy.

The maintenance energy requirement (MEm) of pregnant rats and net energetic efficiency for fetal growth during late pregnancy were examined by regression analysis. Pregnant rats, weighing about 180 g, were fed on 20% casein diet during early-mid pregnancy and then divided into three groups--ad libitum-fed, 50% food restricted, or starved. A linear relation between the energy balance (Y, kcal/100 g BW/day) and the metabolizable energy intake (X, kcal/100 g BW/day) was obtained as Y = 0.81 X-14.83 (n: 17, r = +0.99, p less than 0.001). The X-intercept, MEm, was calculated to be 18.31 kcal/100 g BW/day. Pregnant animals fed ad libitum retained 6.1 and 1.1 kcal of energy daily in their conceptuses and their own body, respectively, during late pregnancy. Assuming that the net efficiency of maternal energy deposition is equal to that for size- and age-matched nonpregnant rats, the net energetic efficiency for fetal growth was calculated to be 82%. This value was very close to the net efficiency for weanling rats reported previously, suggesting that the net energetic efficiency for maximum growth in well-nourished rats is about 82%.

Animals↗
PubMed1986

Characterization of carcinoembryonic antigen-specific monoclonal antibodies and specific carcinoembryonic antigen assay in sera of patients.

Six murine monoclonal antibodies (mAbs) reactive with carcinoembryonic antigen (CEA) were prepared. Four of these, CA204, CA205, CA206 and CA208, were specific to purified CEA whereas the other two, NA201 and NA203, were also reactive with the non-specific cross-reacting antigen (NCA). These mAbs were all IgG1, except one IgG2a (CA206), with high affinities for CEA. NA203, CA204 and CA208 appear to define three different epitopes on the CEA molecule as determined by competitive binding assay. These mAbs also reacted with CEA-producing cells. The treatment of the cells with tunicamycin did not affect the binding of the mAbs to CEA-producing cells. None of the above mAbs bound to CEA-related antigens, NCA-2, alpha 1-acid glycoprotein, or blood group antigens. The combination of CA208 (solid phase) and CA204 (tracer) was used to construct a sensitive CEA-specific sandwich ELISA to detect CEA in the sera of patients with various malignant and non-malignant diseases. Particularly when CEA values were low in sera from non-cancerous patients, the above mAbs sandwich assay showed reduced background reactivity with NCA-like substances and permitted the detection of CEA at a level as low as 1 ng/ml.

Antibodies, Monoclonal↗
PubMed1986

[Conditions of the primary culture for rat hepatocytes and plasminogen activator release].

The conditions of primary culture for rat hepatocytes was investigated on the releasing effect of Plasminogen Activator (PA). The culture method using Collagen Coated Dish (CCD-method) which is currently available and the ordinary culture method using Plastic Culture Dish (PCD-method) were employed for that purpose in a comparative way. The effect of the addition of some supplements, that is FN, Aprotinin, EGF were also investigated. The following results were obtained. The dissociated rat hepatocytes formed a monolayer with pavementlike morphology at 24-48 hours after seeding. No difference was observed in the morphology of hepatocytes during the culture period between the two methods, although CCD-method allowed 120 hours culture, whereas PCD-method allowed 72 hours. The PA activity was demonstrated on the hepatocytes by either culture method according to the fibrinolysis autography. The cultured hepatocytes released PA into the medium continuously as long as the viability and morphology of the cells were maintained in good state. The PA activity reached the maximum after 96 hours culture in CCD-method, whereas it reached the maximum after 48 hours in PCD-method. The addition of Aprotinin to the culture medium was not necessary for PA release in CCD-method in contrast to PCD-method. When EGF was discontinued in the culture medium, the release of PA was reduced in association with the occurring of morphological disintegration of hepatocytes.

Animals↗
PubMed1986

Preparation of human monoclonal antibodies of IgG type to gastro-intestinal cancer-associated antigen.

The B lymphocytes from pleural effusion of a gastric cancer patient were fused with murine myeloma cells (X63-Ag8.653). Thirty-four out of 62 clones were found to secrete human monoclonal antibodies (23 IgGs and 11 IgMs) by means of enzyme-linked immunosorbent assay. Fourteen monoclonal antibodies were tested for histological reactivity with cancer and normal tissues by immunoperoxidase staining. Among them, two monoclonal antibodies reacted rather specifically with gastro-intestinal cancerous tissues. The human monoclonal antibody (HMoAb) 3B7 (IgG) reacted strongly with 4 out of 5 gastric carcinoma tissues and 2 out of 5 colonic carcinoma tissues, but did not react with non-cancerous tissues (stomach, colon, liver, pancreas and lung). In addition, HMoAb 3B7 reacted heterogeneously with autologous gastric carcinoma tissue sections. The hybridoma 3B7 has continued producing human monoclonal antibody for 12 months after fusion. By chromosomal analysis, it was shown that hybridoma 3B7 retains both human and mouse chromosomes. HMoAb 3B7 may be useful for research on tumor-associated antigens and therapeutic techniques.

Antibodies, Monoclonal↗
PubMed1986

[Chemotherapy of renal cell carcinoma. 2. Combined chemotherapy using ACNU and VBL].

Nineteen patients with renal cell carcinoma who had undergone radical nephrectomy have been treated with a combination of chemotherapy and partly hormonal therapy using ACNU, vinblastine and chloromadinone acetate. The efficacy of the combination therapy in advanced renal cell carcinoma was studied and only one out of nineteen cases having lung and pleural metastasis shows no change lasting from one to eighteen months. The prophylactic efficacy was studied in eighteen patients with stage I to IVA renal cell carcinoma (contained one patient with stage IVA renal cell carcinoma who had undergone radical nephrectomy and coecum resection for coecum invasion). Tumor recurrence occurred in 5 cases, that is 5 cases within 1 year and 1 case within 2 years. The combination of chemotherapy using ACNU & vinblastine must be used carefully for severe side effects.

Adult↗
PubMed1986

[A phase II study of mitoxantrone in malignant lymphoma].

A phase II study of mitoxantrone (MIT) was performed in 13 cases of refractory malignant lymphoma, 1 of Hodgkin's disease and 12 of non-Hodgkin lymphoma. The twelve non-Hodgkin lymphomas were previously treated with adriamycin. MIT was diluted in 50 approximately 100 ml saline solution and intravenously administered by drip infusion in 15 approximately 30 minutes. The dose of MIT was 3 mg/m2/day for 5 days (A) or 10 approximately 14 mg/m2/day, for 1 day (B). There were 2 CR, 1 MR, 1 NC and 2 PD among 8 cases treated by schedule A, and two cases were not evaluable. With schedule B, there was 1 MR among 5 cases, and four cases were not evaluable. In the 7 evaluable cases, remission rate was 2/7 (29%) with remission durations of 6+ weeks and 55 weeks. The dose limiting toxicity was granulocytopenia but no serious infection was observed. With schedule A, it was difficult to repeat the treatment every 3 weeks because of the delay in granulocyte recovery. Gastrointestinal toxicities were observed in about half of the treatment courses but they were mild in degree. A prolongation of QTc (greater than 0.44) was observed in 3 cases (4 treatment courses) among 9 cases (10 treatment courses) whose baseline QTc values were within normal limits. Baseline QTc values were above the normal limit in 4 cases and in two of them, QTc showed further prolongation after MIT treatment. No arrhythmia or congestive heart failure was observed.

Adult↗