Mechanisms of the adsorption of oxygen molecules and the subsequent oxidation of the reconstructed dimers on Si(001) surfaces.
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Journal Article↗
Biomedical subjects
S Oikawa
Publications and source records attributed to S Oikawa.
Gene therapy for carcinoembryonic antigen-producing human lung cancer cells by cell type-specific expression of herpes simplex virus thymidine kinase gene.
A carcinoembryonic antigen (CEA)-producing human lung cancer cell line (A549), a nonproducing human lung cancer cell line (CADO-LC9), and a human uterine cervical cancer (HeLa) were transfected with the herpes simplex virus thymidine kinase (HSV-TK) gene regulated by 445 nucleotides upstream from the translational start of CEA gene. Fifty % growth inhibitory concentration of ganciclovir (GCV) was 0.57 micron for HSV-TK-transfected A549; relative sensitivity to GCV was more than 1000 times higher compared to the 50% growth inhibitory concentration of the parental cell line. Both CADO-LC9 and HeLa transfected with HSV-TK were still resistant to GCV. There was no difference in either morphology or doubling time between HSV-TK-transfected and parental clones. Injections (i.p.) of GCV resulted in significant regression of HSV-TK-transfected A549 tumors in nude mice. These data show the possibility of gene therapy using the cell type-specific promoter of CEA gene against CEA-producing adenocarcinoma of the lung.
Adenocarcinoma↗
[Kidney diseases caused by metabolic disorders of carbohydrate and lipids].
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Fabry Disease↗
Non-proteolytic release of carcinoembryonic antigen from normal human colonic epithelial cells cultured in collagen gel.
Recent studies have shown that, even with a minimal content of carcinoembryonic antigen (CEA), normal human colonic epithelial cells express substantial amounts of CEA mRNA and colonic mucosal fragments cultured in vitro produce CEA quite actively, indicating that CEA should no longer be considered to be of an oncofetal nature. To understand the basis of the usefulness of CEA as a tumor marker, we analyzed the release of CEA, a glycosyl-phosphatidylinositol (GPI)-anchored protein, from colonic epithelial cells, by culturing isolated colonic crypts in collagen gel. The crypts appeared to preserve their morphological and biochemical integrity in the gel for at least 16 hr, and released CEA spontaneously. Three forms of CEA--spontaneously released CEA, CEA liberated with phosphatidylinositol-specific phospholipase C (PI-PLC) and CEA in cell lysates--were indistinguishable on SDS-PAGE. This is in contrast to recombinant CEA spontaneously released from CHO transfectants, which showed a smaller molecular mass than that of PI-PLC-cleaved recombinant CEA. By phase separation using Triton X-114, CEA in the cell lysates of crypts was separated mostly into the detergent phase, while the spontaneously released and the PI-PLC-cleaved CEA were separated into the aqueous phase. When the cells were metabolically labeled with the precursors of the GPI-anchor, 3H-ethanolamine but not 3H-palmitic acid was found in the spontaneously released CEA. These findings suggest that, in contrast to the proteolysis-like release of the recombinant CEA from CHO cells, CEA in normal colonic epithelial cells is released by a non-proteolytic cleavage, which probably occurs through the action of some endogenous phospholipase.
Animals↗
Metastatic potential in nude mice of Chinese hamster ovary cells expressing human carcinoembryonic antigen.
The role of carcinoembryonic antigen (CEA) in metastasis was examined using Chinese hamster ovary (CHO) cells which had been transfected with cDNA encoding CEA. When 2 x 10(6) cells of a clone of CEA-expressing transfectants, designated CHO/CEA, were injected intrasplenically into athymic nude mice, 8 out of 8 mice developed liver metastases. In contrast, a vector-transfectant C5 did not at all form metastasis in the assay (0 of 8). There was no difference in growth rate between CHO/CEA and C5 in vivo as well as in vitro. MoAbs to N-domain of CEA markedly inhibited the liver metastasis of CHO/CEA cells, while a MoAb to domain III of the antigen did not. These findings suggest that CEA may play an important role in hepatic metastasis, and that the N-domain of CEA molecule contributes to the function of CEA in metastasis.
Animals↗
Characterization of a species of non-specific cross-reacting antigen (NCA) expressed by human monocytic cell lines: structure and expression during cell differentiation.
It has been documented that human monocytes/macrophages are reactive with antibodies directed to carcinoembryonic antigen (CEA) and non-specific cross-reacting antigens (NCAs), a group of glycoproteins antigenically cross-reactive with CEA, yet the molecules responsible for this antigenic activity have not been fully clarified. In the present study, among 7 myelomonocytic cell lines tested, 2 monoblastoid lines, U-937 and THP-1, were found to express NCA-50/90, a glycosylphosphatidylinositol-anchored cell-adhesion molecule chiefly expressed on granulocytes. The 2 cell lines showed a reaction pattern with 5 distinct anti-CEA and anti-NCA monoclonal antibodies, similar to that of CHO transfectants expressing recombinant NCA-50/90. Immunoprecipitation and SDS-PAGE analyses identified glycoproteins of about 95 and 55 kDa in U-937 and THP-1 cells, respectively. Deglycosylation of the 2 antigens with N-glycanase gave the same apparent molecular mass of about 45,000, which was also the same as that of the deglycosylated form of the recombinant NCA-50/90. Upon Northern-blot analysis, only one band of approximately 2.5 kb was detected in both cell lines with a cDNA probe for NCA-50/90, which has a broad specificity to the CEA gene family members. cDNA cloning demonstrated that the 2.5-kb clones encode the peptide of NCA-50/90. The expression of NCA-50/90 by U-937 and THP-1 was down-regulated at both the protein and mRNA levels during cell differentiation from monoblastoid to monocyte/macrophage-like cells induced by stimulation with phorbol 12-myristate 13-acetate. Our observations suggest that NCA-50/90 is a differentiation antigen of cells of the monocyte/macrophage lineage as well as of the granulocyte lineage.
Antigens, Differentiation, Myelomonocytic↗
Transient and localized expression of bone morphogenetic protein 4 messenger RNA during fracture healing.
Temporal and spatial distribution of a gene encoding murine bone morphogenetic protein 4 (mBMP-4) during fracture repair were investigated in mice by RT-PCR and in situ hybridization. For in situ hybridization, fractured ribs and surrounding tissues were decalcified and hybridized with a mBMP-4-specific complementary RNA probe labeled with digoxigenin-11 UTP. mBMP-4 messenger RNA (mRNA) was not detected in ribs without fracture, whereas it was detected only in the early phase of fracture from 12 to 72 h after the onset of fracture before new cartilage or bone formation. The mBMP-4 mRNAs were present in cells distributed in three distinct regions, namely, the proliferating periosteum, the medullary cavity, and the muscles near the fracture site. These BMP-4-positive cells did not express bone gla protein mRNA, which is a marker of the mature osteogenic cell. RT-PCR also showed a transient increase in the level of BMP-4 mRNA in the early phase of fracture repair. The findings provide us with some new information. (1) The BMP-4 gene is produced by less differentiated osteoprogenitor cells, not by differentiated osteoblasts. (2) The BMP-4 gene is enhanced by the impact of fracture and localized in callus-forming tissue before callus formation. Together with the activities of BMP-4, as was previously described, our results suggest that newly produced BMP-4 gene product is one of the local contributing factors in callus formation in the early phase of fracture healing.
Animals↗
Metastatic potential of human colorectal carcinoma SW1222 cells transfected with cDNA encoding carcinoembryonic antigen.
In order to examine a role of carcinoembryonic antigen (CEA) in metastasis, cDNA encoding CEA was introduced into a clone of human colorectal carcinoma SW1222 cells. Western blot analysis revealed that all transfectants express CEA of 180 kDa while the parent clone does not. In the transfectants, the level of CEA expression in clone 3 was higher than that of clone 1. Clone 3 formed aggregates rapidly after suspended by trypsinization while clone 1 did not. In experimental metastasis assay where tumor cells were injected intrasplenically, clone 3 exhibited a higher liver-metastatic activity than clone 1. Fab fragment of anti-CEA antibody significantly inhibited both the cell aggregation and the liver metastases caused by clone 3. These findings suggested that CEA expressed on the cell surface may play an important role in hepatic metastasis from colorectal carcinoma, possibly through its cell adhesion activity.
Animals↗
Biliary lipid composition in heterozygous familial hypercholesterolemia and influence of treatment with probucol.
The lipid composition of fasting duodenal bile was determined in 11 healthy subjects with normolipidemia and 15 patients with heterozygous familial hypercholesterolemia (FH) (12 with type IIa, three with type IIb). The age distribution among the groups of subjects was similar. In the patients with heterozygous FH type IIa, the mean value for molar percentage of cholesterol and lithogenic index (LI) of bile were significantly higher than those of controls (8.4 +/- 1.0%, 1.47 +/- 0.18 calculated by Hegard, Dam, and Holzbach vs 4.3 +/- 0.4%, 0.81 +/- 0.07, respectively). The value of LI in the patients with FH type IIb was also found to be significantly higher than that of the controls. In the patients with heterozygous FH type IIa, we observed both a significant decrease in the molar percentages of glycochenodeoxycholic acid, glycoursodeoxycholic acid, and glycolithocholic acid, and a significant increase of taurochenodeoxycholic acid compared to the corresponding values in the controls. Bile analysis of six patients was reexamined during probucol treatment after 16 weeks. Probucol significantly lowered serum cholesterol levels. However, biliary lipid composition and individual bile acid proportions was not altered by the treatment. The results suggest that most of the patients with heterozygous FH have supersaturated bile and are predisposed to cholesterol gallstone formation. In addition, the mechanism by which probucol lowers serum cholesterol appears to be independent of any change in the metabolism of biliary lipid.
Adult↗
Expression and characterization of human bone morphogenetic protein-2 in silkworm larvae infected with recombinant Bombyx mori nuclear polyhedrosis virus.
Recombinant human bone morphogenetic protein-2 (rhBMP-2) was expressed in silkworm larvae, and a milligram quantity of the protein was purified and characterized. The expressed rhBMP-2 was biologically active in terms of induction of alkaline phosphatase activity in MC3T3-E1 cells and ectopic bone formation in mice. On SDS-polyacrylamide gel electrophoretic analysis, the purified protein showed a 16 kDa band under reducing conditions and a 30 kDa band under non-reducing conditions. The silkworm-expressed rhBMP-2 was glycosylated and susceptible to endo-beta-N-acetylglucosaminidase F (endo F) and endo H, but resistant to endo D. Deglycosylated rhBMP-2 treated with endo F retained its biological activity. These results suggest that rhBMP-2 exists as a dimer and disulfide bond(s) are responsible for the dimerization. Moreover, sugar chains have no direct effect on the biological activity of the protein. The availability of a quite large amount of rhBMP-2 has allowed us to study the biological function of this interesting factor in detail.
3T3 Cells↗
A neonatal huge subependymal giant cell astrocytoma: case report.
We report a neonate with a huge subependymal giant cell astrocytoma associated with tuberous sclerosis, with atypical magnetic resonance imaging findings. The neonatal subependymal giant cell astrocytoma is rare, and we discuss the difficulty in its diagnosis and treatment.
Brain Neoplasms↗
[A study on stressful life events of workers in Japan].
The experience rates of eighteen life events of Japanese workers were surveyed and the strength of each of the events was evaluated by a self-reported questionnaire. The fifteen professions surveyed included construction, transport, mailing, chemical production, banking, newspaper, TV services, commercial publishing, advertising, teaching and civil service. The number of workers who answered was 18,657 males and 4,443 females, aged 20 to 59 years. The male workers were divided and analysed in six job groups: clerical workers (n = 5,866), professionals (n = 3,696), blue collar day workers (n = 1,623), blue collar night or shift workers (n = 3,191), drivers (n = 1,663) and construction workers (n = 2,466). They were divided into groups and compared according to job, sex and five different age groups. The highest experience rate in each of the life events such as family trouble for both sexes, death of a family member, financial trouble and anxiety, death of a close friend, dissatisfactory transport to workplace or job, respectively. Comparing the experience rates between males and females we found no significant difference for five items. However, other items had higher experience rates for males than for females with the exception of family trouble. In regard to the age characteristics of each of the life events, as the age increased the experience rates of health-related life events such as the death of a spouse, child, family member or close friend and one's own illness or injury became higher. In contrast, the experience rates of items such as moving to a worse residence and failure in a school or training program became lower as the age increased for both sexes. Among job groups, construction workers had the highest experience rates of most life events except for the item of dissatisfactory transport to the workplace or job. Among other job groups, drivers had higher experience rates in the following four items: re-employment, death of spouse, divorce and financial trouble and anxiety. Blue collar day workers had higher rates for failure in school or training program and family trouble. The blue collar night or shift workers had higher rates for failure in school or training program and dissatisfactory transport to the workplace or job. The mean values of strength in six life events: re-employment, death of a family member, death of a close friend, serious physical illness, dissatisfactory transport to the workplace or job and family trouble were stronger in females than in males.(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
A rapid colorimetric assay for carcinoembryonic antigen (CEA)-mediated cell adhesion and analysis of CEA domains involved in the adhesion.
A colorimetric microadhesion assay that allows the quantitative determination of carcinoembryonic antigen (CEA)-mediated homophilic cell adhesion to CEA immobilized on 96-well polyvinyl chloride plates is described. Chinese hamster ovary (CHO) cells transfected with a full-length CEA cDNA were used as indicator cells. After dislodging nonadherent cells, specifically bound cells were quantified by a colorimetric analysis based on the ability of live cells to reduce the dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to a blue formazan product. The domains of CEA responsible for the homophilic cell adhesion were analyzed by inhibition assays using anti-CEA monoclonal antibodies whose reactive domains were already known. The involvement of domain N and possibly subdomain A3 of CEA in the homophilic cell adhesion has been suggested.
Animals↗
[Clofibrate treatment of hyperlipoproteinemia].
Clofibrate has cholesterol- and triglyceride-lowering effect. They affect on the various points in the metabolic pathway of lipoproteins. They improve VLDL-synthesis in liver and increase the activity of LPL and hepatic TG lipase. As the results, HDL-cholesterol increases and LDL decreases. Therefore Clofibrate decreases not only plasma triglyceride but cholesterol levels. It has been reported that Clofibrate have a preventive effect on cardiovascular disease. So these agents are useful in the treatment for hyperlipidemic patients with or without atherosclerosis.
Cholesterol↗
[DNA diagnosis: its induction, problem and future--with special reference to congenital goiter].
PCR technique is a powerful tool for genetic analysis of various diseases including infectious diseases, inherited diseases and malignant tumors. Some of our experiences and problems in gene level diagnosis using mainly the PCR technique newly introduced to our clinical laboratory were discussed. A case of congenital goiter in which the analysis at the gene level was the first demonstration of a mutation associated with the abnormal expression of the thyroglobulin gene in man, is also presented. The direct demonstration from the sputum of the presence of M. tuberculosis DNA by PCR will be a great benefit to the clinician in the diagnosis and treatment of tuberculous infection. At present, it is possible to report the results within 2 days from the submission of samples, but further considerations on the sensitivity and specificity are required. The clinical laboratory will be required to accumulate sufficient knowledge of gene level analysis of various disease conditions and master the techniques.
Adult↗
Production and characterization of monoclonal antibodies to N-domain and domain III of carcinoembryonic antigen.
In order to obtain MoAbs against N-domain or domain III of carcinoembryonic antigen (CEA), mice have been immunized with a recombinant deleted CEA which was devoid of most of domains I and II. Of the nineteen MoAbs established, ten MoAbs were reactive with the N-domain of CEA, and others recognized the domain III. All Fab fragments of the MoAbs against the N-domain significantly inhibited homophilic cell adhesion mediated by CEA, whereas that of normal mouse IgG or control MoAb (anti-HLA class II) did not. Among the Fab fragments of MoAbs against the domain III, three inhibited the cell adhesion slightly, while five enhanced and one had no effect. These findings suggest that the N-domain of CEA plays an important role in the cell adhesion, and that the domain III is also involved in the binding. The MoAbs described in this study will be useful to elucidate the functional roles of the domains of CEA molecule.
Animals↗
Effects of high-density lipoprotein particles containing apo A-I, with or without apo A-II, on intracellular cholesterol efflux.
Previous reports have shown a differential effect of high-density lipoprotein (HDL) particles which contain apolipoprotein (apo) A-I without apo A-II (Lp A-I) and particles containing both apo A-I and apo A-II (Lp A-I/A-II) on cholesterol efflux from the mouse adipocyte cell line Ob1771, with Lp A-I and Lp A-I/A-II being active and inactive cholesterol efflux promotors, respectively. The present study was conducted to examine the roles of these two populations of apo-specific HDL particles on reverse cholesterol transport from cholesterol-loaded human skin fibroblasts and bovine aortic endothelial cells. The ability of HDL particles to remove intracellular cholesterol was tested by measuring depletion of the substrate pool for acylCoA:cholesterol acyltransferase (ACAT) and efflux of newly synthesized cholesterol, while removal of plasma membrane cholesterol was assessed by measuring efflux of [3H]cholesterol from prelabeled cells. Lp A-I and Lp A-I/A-II isolated from HDL2, HDL3 or plasma by immunoaffinity techniques each decreased esterification of cholesterol by both fibroblasts and endothelial cells. A mixture of Lp A-I and Lp A-I/A-II isolated from HDL3 decreased cholesterol esterification by fibroblasts in an additive manner, thus demonstrating that Lp A-I/A-II did not inhibit Lp A-I-mediated cholesterol efflux. Both Lp A-I and Lp A-I/A-II promoted efflux of sterol newly synthesized by fibroblasts, and no significant differences were observed between the apo-specific particles. Apo-specific particles were also similarly effective at preventing the accumulation of LDL-derived cholesterol in cholesterol-depleted fibroblasts. Efflux of [3H]cholesterol from plasma membranes was stimulated to similar extents by Lp A-I and Lp A-I/A-II isolated from either HDL2, HDL3 or plasma. Thus, the apo-specific HDL particles Lp A-I and Lp A-I/A-II are both effective promoters of cholesterol efflux from fibroblasts and aortic endothelial cells.
Animals↗