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Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 865 records · Page 48Linked to original sources
PubMed1985

Effects of intra-arterially infused biodegradable microspheres containing mitomycin C.

We prepared biodegradable microspheres containing about 5% mitomycin C (MMC) and of 45 +/- 8 microns in diameter. These preparations were infused into the rat hepatic artery as a preclinical model of intra-arterial infusion treatment for patients with inoperable hepatic tumor. The leaked MMC levels in the hepatic vein decreased below the assay limitation 2 hours after conventional MMC injection, whereas in the case of MMC microsphere the leaked drug levels were maintained at almost the same concentration for over 2 hours after infusion. The entrapped period of MMC microspheres within the hepatic artery was at least 2 weeks, and the necrobiotic foci due to antitumor effects of the condensed MMC released from the microspheres were observed in the area fed by these entrapped arterioles. This phenomenon was never observed in the case of conventional MMC and placebo microspheres. Intra-arterial infusion of MMC microspheres may be a promising clinical treatment for patients with malignant hepatic tumor.

Animals↗
PubMed1985

Long-term survivors of colorectal cancer with unresectable hepatic metastases.

Five patients with colorectal cancer and unresectable synchronous liver metastases have survived for over five years at this writing. Four of the five had multiple metastases over both lobes, as diagnosed preoperatively, and the other had multiple metastases in the right lobe not evident preoperatively. The primary foci were excised completely in four patients. For one patient with multiple metastases limited to the right lobe, the postoperative cancer chemotherapy prescribed was intravenous mitomycin C (MMC; 12 mg) and oral ftorafur (a derivative of 5-FU) for a total dose of 291 gm over 63 weeks. The remaining four patients underwent postoperative intra-arterial infusion therapy with the average total dose of 20.5 mg of MMC plus 5600 mg of 5-FU; subsequently, they received protracted chemotherapy with oral ftorafur of 354 gm as an average, with little or no side effects. In these four patients, duration of intra-arterial treatment was an average of 3.2 weeks, and the subsequent oral treatment continued for an average of 85 weeks. Recent hepatic echography and CEA determinations show these patients to be free from intrahepatic metastasis.

Administration, Oral↗
PubMed1985

Regulation of immune responses via genetically restricted cellular interactions. II. I-region-restricted cooperation between idiotypic and anti-idiotypic B lymphocytes.

Immunization of BALB/c mice with MOPC-104E myeloma protein induced idiotype-specific enhancing cells which acted on anti-dextran antibody-producing cells. The enhancing cells have surface phenotypes of B cells. Using BALB/c H-2 congenic strains, it was found that the cooperation between anti-idiotypic-enhancing B lymphocytes and dextran-primed B lymphocytes was controlled by major histocompatibility gene complex. Here we have described the loci which restrict the successful cooperation between B lymphocytes, wherein it was revealed that the interaction was restricted to the I-A and I-E subregions in H-2k haplotype and the I-A subregion in H-2b haplotype. Utilizing several monoclonal antibodies specific for Ia antigens, it was revealed that the enhancing B lymphocyte activity was completely inhibited by the pretreatment of antibody-producing B cells with anti-Ia.7 in H-2d haplotype as well as H-2k, and with anti-I-A antibody in H-2b haplotype. The results suggest that the anti-idiotypic B-lymphocyte response to the self idiotype is under control of H-linked immune response (Ir) gene.

Animals↗
PubMed1985

Tritiated thymidine radioautographic study on the origin and renewal of secretin cells in the rat duodenum.

The origin and renewal of secretin cells in the duodenum were investigated using the unlabeled antibody peroxidase-antiperoxidase technique and radioautography in rats killed at various times after single or multiple injections of [3H]thymidine. Secretin cells were spatially distributed from the upper crypt to the villus tip, being particularly numerous in the upper two-thirds of the duodenal villi. After a single injection of [3H]thymidine, there were no labeled secretin cells, indicating a lack of self-replicating activity. After repeated injections of the isotope, labeled secretin cells appeared and increased in number. They first occurred at the upper part of the crypt and the lower part of the villus, and later at the villus tip. All these cells were found to be labeled after continuous labeling for 120 h, which is considered to be the renewal time for this cell population.

Animals↗
PubMed1985

Immunoelectron microscopic localization of growth hormone in the pituitary glands of two teleosts, tilapia (Sarotherodon mossambicus) and amago salmon (Oncorhynchus rhodurus).

Growth hormone (GH) cells were investigated with the protein A-gold technique on the pituitary glands of tilapia (Sarotherodon mossambicus) and amago salmon (Oncorhynchus rhodurus). By the use of specific antiserum against tilapia GH to both species, the immunoreactive gold particles were demonstrated to be preferentially located on the secretory granules of the GH cells. Specimens fixed only with periodate-lysine-paraformaldehyde (PLP) preserved the hormonal antigenicity well. Osmium postfixation, although considerably reducing the antigenicity and thus resulting in a decrease in number of the gold particles on the GH cells, gave much more satisfactory ultrastructural preservation and immunoreactive localization of immunoreactive material. This investigation demonstrated that, after combined fixation with PLP and PLP-osmium, we could determine the function of a given cell type in various endocrine organs as well as the precise antigenic sites in such cells.

Animals↗
PubMed1985

Generation of T cell growth factor (TCGF)- dependent splenic lymphoid cell line with cell-mediated immunosuppressive reactivity against syngeneic murine tumor.

Splenic T cells obtained from tumor-bearing mice could be cultured with T cell growth factor (TCGF) for over 12 months. The TCGF-dependent lymphoid cell line strongly inhibited cell-mediated anti-tumor immunity directed against syngeneic tumor. However, the suppression was non-specific for the given tumor. The cell line expanded with TCGF expressed a phenotypic characterization of T cells defined by monoclonal anti-Thy-1.2 antibody.

Animals↗
PubMed1985

Transposon-like sequences in extrachromosomal circular DNA from mouse thymocytes.

Small polydisperse circular (spc) DNA was isolated from mouse thymocytes and cloned into the HindIII site of lambda vector Charon 7. Fifty-six recombinants from this spc DNA library were analyzed. R repeats, which were originally found near immunoglobulin genes, were enriched in spc DNA clones relative to their representation in the chromosome. In one clone, the R sequence was linked to Bam and MIF sequences and the contiguous arrangement was truncated from both ends. In another clone, composite Bam/R and R repeats existed as a pair in inverted repeat orientation. Truncation occurred from the 5' side without affecting the 3' ends. In both clones, short direct repeats flanked the repeated sequences. The possible role of R sequences in transposition and circular formation is discussed.

Animals↗
PubMed1985

Mitomycin C carrying microspheres as a novel method of drug delivery.

Biodegradable albumin microspheres containing about 5% mitomycin C (MMC) were prepared in an average diameter of 45 +/- 8 microns by heat denaturation in oil at 120 degrees C and/or cross-linking with glutaraldehyde. These MMC microspheres released, in vitro, about 20% of the contained MMC for over 3 days, and they were intra-arterially infused into albino rabbits and Wistar rats, as a preclinical model of intra-arterial infusion treatment for patients with inoperable hepatic tumor. We infused these microspheres into the femoral artery of rabbits with a VX-2 tumor implanted into the flank of the hindleg. High levels of MMC were maintained for several hours in the tumor and the entrapped MMC microspheres were detected within arterioles in the VX-2 tumors. The growth of VX-2 tumor was inhibited considerably, compared to findings in the control rabbits given conventional MMC. In the next studies, MMC microspheres were infused into the rat hepatic artery, and the levels of MMC in the hepatic vein blood were maintained at much the same concentration for over 2 hours after the infusion, in marked contrast to rapid decreases in the conventional MMC. Histologic findings revealed that MMC micro-spheres were entrapped within the hepatic arterioles for over 2 weeks and released biologically active MMC into the neighboring tissues for prolonged periods of time.

Albumins↗
PubMed1985

The presence of essential histidine residues in manganese(III)-containing acid phosphatase from sweet potato.

Chemical modification studies of manganese(III)-containing acid phosphatase [EC 3.1.3.2] were carried out to investigate the contributions of specific amino-acid side-chains to the catalytic activity. Incubation of the enzyme with N-ethylmaleimide at pH 7.0 caused a significant loss of the enzyme activity. The inactivation followed pseudo-first-order kinetics. Double log plots of pseudo-first-order rate constant vs. concentration gave a straight line with a slope of 1.02, suggesting that the reaction of one molecule of reagent per active site is associated with activity loss. The enzyme was protected from inactivation by the presence of molybdate or phosphate ions. Amino acid analyses of the N-ethylmaleimide-modified enzyme showed that the 96%-inactivated enzyme had lost about one histidine and one-half lysine residue per enzyme subunit without any significant decrease in other amino acids, and also demonstrated that loss of catalytic activity occurred in parallel with the loss of histidine residue rather than that of lysine residue. Molybdate ions also protected the enzyme against modification of the histidine residue. The enzyme was inactivated by photooxidation mediated by methylene blue according to pseudo-first-order kinetics. The pH profile of the inactivation rates of the enzyme showed that an amino acid residue having a pKa value of approximately 7.2 was involved in the inactivation. These studies indicate that at least one histidine residue per enzyme subunit participates in the catalytic function of Mn(III)-acid phosphatase.

Acid Phosphatase↗
PubMed1985

Iron-containing granules in the syncytiotrophoblast of the human chorionic villi.

The syncytiotrophoblast of the human chorionic villi during earlier stages of gestation contains abundant granules derived from Golgi complexes. The granules often include very electron-dense lamellae in their interior, and X-ray microanalysis revealed the presence of iron in these lamellae. It is, therefore, supposed that iron particles absorbed into the syncytiotrophoblast are transported to Golgi complexes and integrated into these lamellae. No evidences that the granules are released from the cells by exocytosis have been proved. Thus, one possibility to their nature might be considered, that is they play a role in lysosomal storage of iron during earlier stages when the capillaries in the chorionic stroma are undeveloped and so have little ability to transport iron into the fetal circulation.

Chorionic Villi↗
PubMed1985

Two-site "simultaneous" immunoassay with monoclonal antibodies for the determination of surfactant apoproteins in human amniotic fluid.

Monoclonal antibodies against human surfactant apoproteins were prepared, which recognized 37, 34, and 62 kilodalton proteins in human lung lavage fluid and amniotic fluid. Two-site "simultaneous" immunoassay for the surfactant apoproteins was developed using the monoclonal antibodies. The assay was capable of measuring 10-640 ng of the apoproteins per ml of human amniotic fluid. The immunoassay was used to quantitate the apoproteins in 59 amniotic fluid samples from 23 to 41 wk gestation. The concentration of the surfactant apoproteins at less than 30 wk gestation was very low (mean 0.84 micrograms/ml). It then increased 6.5-fold from 34 to 36 wk gestation and 15.5-fold at more than 37 wk gestation. The simultaneous immunoassay with the monoclonal antibodies presented herein seems to be ideal for clinical use because of its high specificity, sensitivity, rapidity, simplicity, and a continuous unlimited supply of the antibodies. The results in this study show that the clinical use of the two-site simultaneous immunoassay with monoclonal antibodies to pulmonary surfactant apoproteins can predict fetal lung maturity more precisely.

Amniotic Fluid↗
PubMed1985

Erythrocyte insulin receptor and glucose tolerance test in children treated with prednisolone.

Insulin receptors of erythrocytes and oral glucose tolerance test (O-GTT) were investigated in sixteen children treated with prednisolone for various diseases. Ten patients (Group 1) received low doses of prednisolone (0.2-0.5 mg/kg body weight/day) and six patients (Group 2) received higher doses of prednisolone (1.5-2.0 mg/kg body weight/day). Compared to the values for controls, the sums of blood glucose (sigma BS) at O-GTT in both group 1 and group 2 patients were significantly elevated. (422 +/- 75 mg/dl, p less than 0.01 Group 1; 419 +/- 39 mg/dl, p less than 0.01 Group 2; 338 +/- 41 mg/dl controls) Significant differences were not observed in the sums of insulin concentration at O-GTT, fasting blood concentration and basal insulin levels among these two groups and the controls. There was a significant increase in the maximum insulin binding in group 2 (9.13 +/- 0.68% in group 2, 7.97 +/- 1.06% in controls, p less than 0.05), but not in group 1 (8.59 +/- 1.82%). There is no significant difference in binding affinity or the number of receptors between any of these two patients' groups and the controls. When patients in group 1 and group 2 were combined, sigma IRI levels were significantly elevated in the patients (p less than 0.05). These results suggested that prednisolone treatment with a smaller dosage as well as with the higher dosage resulted in a carbohydrate intolerance, the main cause of which is located in a postreceptor step (or steps) of insulin action.

Adolescent↗
PubMed1985

The negative correlation between prolactin and ionic calcium in cord blood of full term infants.

Total serum calcium (Ca), ionic calcium (Ca++), phosphorus, magnesium, total protein, immunoreactive parathyroid hormone (iPTH), calcitonin (iCT) and prolactin (iPRL) were measured in 30 paired samples of cord and maternal blood obtained at term delivery. In the cord blood, the concentrations of Ca, Ca++, phosphorus, magnesium, albumin, iCT and iPRL were all higher, and the concentrations of total protein and iPTH lower than in the maternal blood. The calcium binding capacity of albumin assessed with the equation (Ca-Ca++)/albumin, was similar at a given concentration of Ca in both the maternal and fetal circulations. There was a significant positive correlation between cord Ca++ and maternal Ca or Ca++, and a significant negative correlation between Ca++ and iPRL in cord blood. These data suggest that there is an active system transporting calcium from mother to fetus through the placenta, and PRL is the only one of the three hormones which was correlated with ionic calcium values in the fetus. The negative relationship between Ca++ and iPRL in the cord blood suggests an inhibitory effect of the relative hypercalcemia on PRL secretion in the fetus.

Calcitonin↗
PubMed1985

Carnosine as a histidine source: transport and hydrolysis of exogeneous carnosine by rat intestine.

Transport and metabolism of L-carnosine (beta-alanyl-L-histidine) were studied in rat small intestine. Carnosine administered orally was found in rat serum as well as small intestine and liver, followed by an increase of histidine. At ten minutes after carnosine infusion per os, the carnosine content of the hepatic portal vein increased with the dose. On the other hand, the histidine content increased two-fold but did not vary with the dose. These results suggest that part of the carnosine administered orally is hydrolyzed to beta-alanine and histidine in the small intestine. Carnosinase activity was present in many rat tissues and was most active in kidney in the presence of Mn2+. However, in the absence of Mn2+ carnosinase activity in small intestine was found to be the same level as that of kidney. A study has been made of the distribution of carnosinase along the small intestine of adult rat. The dipeptidase was distributed along the whole length of the small intestine with maximum hydrolytic activity in the jejunum, and was localized in the cytosol of the intestinal mucosa. Antiserum prepared against carnosinase purified from kidney inhibited the activity of small intestine as well as that of kidney.

Animals↗
PubMed1985

[Anticancer treatment with a combination of antimetabolites of polyamine and pyrimidine].

A combined efficacy of the polyamine antimetabolites, alpha-difluoromethylornithine (DFMO) and methylglyoxal-bis-guanylhydrazone (MGBG) with two fluorinated pyrimidines was studied. DFMO, MGBG, 5-FU and 5'-deoxy-5-fluorouridine (5'-DFUR) were administered intraperitoneally to BALB/c nu/nu mice bearing xenotransplanted human gastric cancer for 5 consecutive days. Similar antitumor efficacies were observed in 3 groups treated with DFMO plus MGBG, DFMO, MGBG plus 5-FU as well as DFMO, MGBG plus 5'-DFUR. The two groups on 5-FU or 5'-DFUR alone did not differ in antitumor effects from the control, although reasonable levels of 5-FU were involved in tumor tissues. Hepatic and splenic 5-FU levels after 5-FU administration were significantly higher than those after 5'-DFUR, and marked decrease in mouse body weight was caused by 5-FU alone as well as 5-FU plus polyamine antimetabolites for 5 consecutive days. DNA biosynthesis and spermine levels in the tumor tissues on day 2 after cessation of the treatments dropped in 3 groups with DFMO plus MGBG, DFMO, MGBG plus 5'-DFUR as well as DFMO, MGBG plus 5-FU, while on day 6 there was little difference between the control and treated groups. These data suggest that combination with 5-FU or 5'-DFUR does not enhance the antitumor activity of polyamine antimetabolites by this experimental regimen.

Animals↗