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Biomedical subjects

A Haugen

Publications and source records attributed to A Haugen.

At least 109 records · Page 6Linked to original sources
PubMed1981

Explant culture of rat esophagus in a chemically defined medium.

Esophagus from adult male CDF rats was cultured for a period of 28 d in CMRL-1066 medium supplemented with pyruvic acid, HEPES buffer, beta-retinyl acetate, and antibiotics. Morphological, radioautographic, and biochemical studies indicated that the survival of the tissue in serum-free medium was equivalent to that in medium containing 5% heat-inactivated fetal bovine serum. There was a relatively constant uptake of [3H]thymidine into DNA and [3H]leucine into protein of the esophageal explants during the incubation. Only the basal cells of the epithelium incorporated [3H]thymidine into their nuclei. The normal morphology of the tissue was preserved when the explants were maintained at both 37 and 30 degrees C, and in either 50 or 20 % 02. Ninety-five percent O2 was highly toxic to the cells of the explants. This culture system should be suitable for a variety of investigations in esophageal cell differentiation and carcinogenesis.

Animals↗
PubMed1981

Monoclonal antibody to aflatoxin B1-modified DNA detected by enzyme immunoassay.

Monoclonal antibodies were obtained after fusion of mouse P3 X 63 myeloma cells with spleen cells isolated from BALB/c mice that had been immunized with aflatoxin B1-adducted DNA complexed with methylated bovine serum albumin. Selected hybridomas were found to produce monoclonal antibodies specific for aflatoxin B1-modified DNA containing both the 2,3-dihydro-2-(N7-guanyl)-3-hydroxyaflatoxin B1 and the putative 2,3-dihydro-2-(N5-formyl-2',5',6'-triamino-4'oxo-N5-pyrimidyl) -3-hydroxyaflatoxin B1, suggesting that these DNA adducts share a common antigenic determinant. The monoclonal antibody was not reactive towards the free aflatoxin B1-guanine adducts in solution, seven other aflatoxin derivatives, or benzo[a]pyrene-adducted DNA. A noncompetitive ultrasensitive enzyme radioimmunoassay could measure 15 fmol of aflatoxin B1-DNA adducts in 10 ng of DNA and was at least 100-fold more sensitive than the standard enzyme-linked immunosorbent assay. Competitive enzyme-linked immunosorbent assay with these monoclonal antibodies reliably quantitated aflatoxin B1 adducted in vivo to rat liver DNA at adduct levels of one aflatoxin B1 residue per 250,000 nucleotides. The competitive ultrasensitive enzyme radioimmunoassay was determined to be at least 6-fold more sensitive than the competitive enzyme-linked immunosorbent assay in analysis of aflatoxin B1-adducted DNA. Therefore, enzyme immunoassay using monoclonal antibodies will be useful analytical tools for studying both the molecular interactions of aflatoxin B1 with DNA and the occurrence of aflatoxin B1-DNA adducts in biological specimens from people exposed to this environmental carcinogen.

Aflatoxin B1↗
PubMed1981

Responsiveness of fetal rat brain cells to glia maturation factor during neoplastic transformation in cell culture.

The effect of partially purified extracts from adult pig brains containing a glia maturation protein factor (BE) has been investigated on neural cells during carcinogenesis. Pregnant BD IX-rats were given a single transplacental dose of the carcinogen ethylnitrosourea (EtNU) on the 18th day of gestation. The brains of the treated fetuses were transferred to cell culture and underwent neoplastic transformation with a characteristic sequence of phenotypic alterations which could be divided into five different stages. During the first 40 days after explantation (stage I & II) BE induced morphological differentiation of epitheloid neural cells into astrocytes. This occurred in carcinogen treated cells as well as in untreated control cultures. At the same time cells with astrocyte morphology showed accumulation of glial fibrillary acidic protein (GFA) as tested by indirect immunofluorescence with monospecific antibodies against GFA. Thereafter, in the EtNU pre-treated cultures an increased number of cells with astrocyte morphology was seen, and BE further increased the number of cells with long cytoplasmic processes. Control cells were GFA negative, while some few strongly, as well as many weakly, positive cells were seen after treatment with BE (stage III). At the later stages of neoplastic transformation the effect of BE became gradually less, and in tumourigenic cells which occurred after about 200-300 days, only a slight morphological change took place in a few cell lines. No appreciable effect on GFA-content was seen any longer, although some few weakly GFA positive cells could be observed in all permanent cell lines. Fetal rat brain cells therefore seem to become less responsive to this differentiation inducer during neoplastic transformation in cell culture.

Animals↗
PubMed1981

Clonal growth of epithelial cells from normal adult human bronchus.

Normal primary epithelial cell cultures devoid of fibroblastic cells have been developed from tissue explants of adult human bronchi. Conditions for clonal growth of secondary cultures of bronchial epithelial cells were optimized by coculturing the human cells with mitomycin C growth-arrested Swiss 3T3 mouse feeder cells, lowering the calcium concentration of medium M199, and supplementing it with hydrocortisone, insulin, cholera toxin, epidermal growth factor, and 1.25% fetal bovine serum. The epithelial cells grew for an average of 35 population doublings and had the normal human karyotype, expressed keratin and blood group antigen epithelial cell markers, metabolized benzo(a)pyrene, and were capable of differentiating into both ciliated and squamous cells. This culture system makes it potentially possible to investigate various aspects of differentiation and carcinogenesis in human bronchial epithelial cells.

Animals↗
PubMed1979

Ruthenium red binding to cell coat in neoplastic neurogenic cell lines in culture.

The cell coat of cultivated fetal rat brain cells as well as malignant rat neurogenic cell lines in culture were studied by transmission electron microscopy with the ruthenium red staining technique. Some of the transformed cell lines demonstrated alteration in the bindng properties of ruthenium red to the cell surface. Otherwise no significant correlation between the visualized cell coat thickness and neoplastic transformation was noted.

Animals↗
PubMed1979

Fc gamma receptors receptors on fetal rat brain cells during neoplastic transformation in culture after exposure to ethylnitrosourea in vivo.

Fetal rat brain cells, undergoing neoplastic transformation in long-term culture after a single transplacental pulse of N-ethyl-N-nitrosourea on the 18th day of gestation, were investigated for Fc gamma receptors. Rosette assay with cells in suspension and the hemadsorption to cells on coverglasses were used for their detection. The receptors were found on cells after about 2 months in culture. A maximum of 20% of the cells were Fc gamma receptor-positive after 3 months. About 3 weeks later no Fc gamma receptors could be detected. Malignant rat neurogenic cell lines were also negative.

Animals↗
PubMed1979

Cerebellar ganglioglioma. Case report.

This report presents clinicopathological documentation of a nerve-cell tumor in the right cerebellar hemisphere in a young woman. The nomenclature and some other aspects of tumors containing neuronal cells are discussed.

Adult↗
PubMed1979

Transmission electron microscopy of fetal rat brain cells during neoplastic transformation in cell culture.

Fetal rat brain cells were investigated by transmission electron microscopy during neoplastic transformation in long-term cell culture. Before transfer of the cells to culture, BD IX rat fetuses were treated with a single transplacental pulse of N-ethyl-N-nitrosourea (75 micrograms/g body wt) on the 18th day of gestation. During the early stages (3--4 mo), both glia-like and neuron-like cells were present in the culture, and after 2 months they formed complex aggregates ("nodules"). In contrast, corresponding secondary control cultures consisted of flat, epithelioid neural cells without neuron or astrocyte differentiation. After 3 months, cells with neuron morphology gradually disappeared. Some of the remaining cells contained many autophagosomes. After 5 months, rapid proliferation of rather homogeneous, glia-like populations was accompanied by reduction of microfilament bundles and microtubules, as well as atypical nuclei. Ability to form tumors upon sc implantation into syngeneic hosts was not observed until about 3 months later.

Animals↗
PubMed1979

A study of Sézary cells in peripheral blood and skin lesions.

A patient with Sézary syndrome is presented. By phase contrast and scanning electron microscopy Sézary cells were demonstrated in peripheral blood and in skin tissue. Investigation of atypical mononuclear cells seen in the peripheral blood showed that these cells lack receptors for sheep erythrocytes. C3 and Fcgamma. Similarly, an examination of dermal mononuclear cell infiltrates showed that most of the cells lack receptors for sheep erythrocytes, C3 and Fcgamma.

Aged↗
PubMed1978

Induced glial differentiation of fetal rat brain cells in culture: an ultrastructural study.

Primary and secondary cultures of fetal rat brain cells (FBC) from 18th day of gestation have been investigated by scanning and transmission electron microscopy. Primary cultures consisted of a monolayer of flat, undifferentiated epithelioid cells, with some oligodendrocytes, astrocytes and immature neuronal cells. In secondary cultures, cells with glia morphology disappeared. Following addition of extracts from adult rat brains to secondary cultures, a dramatic change of the epithelioid cells took place. They detached from the palstic surface, extruded long cytoplasmic processes with numerous microvilli and cytoplasmic blebs as well as parallel arrays of microtubules and filaments. The differentiated cells resembled astrocytes, and characteristic glia filaments were also observed. An increase of ribosomes and rough endoplasmatic reticulum suggested enhancement of protein synthesis. At the same time S-100 protein and glial fibrillary acidic protein accumulated within the cells. The morphological changes were mostly reversible within 48 h of removal of the brain extract.

Animals↗
PubMed1978

The placental Fcgamma receptors studied using immune complexes of peroxidase.

Immune complexes of horseradish peroxidase (HRP) and rabbit IgG antibodies to HRP were used to study the Fcgamma receptors in normal human placenta. Cryostat sections of placental tissue were incubated with the complexes, and the peroxidase activity was revealed histochemically. The bound complexes were localized to the apical surface of the trophoblasts and endothelial cells of the fetal stem vessels. Binding also occurred within the wall of some fetal vessels, to stromal cells and occasionally to areas corresponding to the trophoblastic membrane. The strongest binding was obtained with immune complexes prepared at slight antigen excess. Eight- to sixteen-fold increased concentration of human and rabbit IgG was needed to block the binding of immune complexes. Bovine and porcine IgG did not block the binding. Treatment of tissue sections with neuraminidase enhanced the binding activity of the receptors. The technique is very convenient for studies of Fcgamma receptors in tissue. However, unfixed frozen placental tissue was not suitable for ultrastructural studies.

Animals↗
PubMed1978

Scanning electron microscopy of neoplastic neurogenic rat cell lines in culture.

The surface structure of a series of malignant neurogenic rat cell lines in culture has been investigated by scanning electron microscopy. Neoplastic transformation was induced by a single transplacental administration of the carcinogen ethylnitrosourea (ENU) to BD-IX rats on the 18th day of gestation. The malignant cell lines were established either by explantation into culture of cells from solid gliomas or neurinomas developed in the offspring, or by transfer of fetal brain cells to culture where they subsequently underwent malignant transformation. A high degree of surface activity was observed, as evidenced by microvilli, filopodia, ruffling membranes and zeiotic blebs. Surface activity was highest in cell cultures giving rise to glioma-like tumours upon re-implantation into syngeneic hosts, and low in those giving rise to neurinoma-like tumours, with one exception. The lowest surface activity was seen in a cell line which was not tumourigenic. High surface activity was mostly correlated with a high degree of aneuploidy. No correlation was apparent with other properties of the neoplastic cell lines, e.g., stem line ploidy and population doubling time in cell culture.

Animals↗
PubMed1978

Surface structure of fetal rat brain cells during neoplastic transformation in cell culture.

The surface microstructure of fetal rat brain cells undergoing neoplastic transformation in long-term cell culture after a single transplacental pulse of 75 microgram N-ethyl-N-nitrosourea/g body weight to the fetal (18th day of gestation) BD IX rat was investigated by scanning electron microscopy. After about 3 weeks of culture, N-ethyl-N-nitrosourea-pretreated fetal rat brain cells showed focal proliferation of neural cells on an underlayer of flat, epithelioid cells. The neural cells exhibited varying forms of numerous dorsal ruffles and an increased number of other surface microprojections. Between the 40th and the 100th day, nodules of bipolar and multipolar neural cells were observed with a complex surface microstructure including many blebs and ruffles and an increased number of microvilli. After 100-210 days, more rapidly proliferating, morphologically altered cells formed "piled-up" foci, which resulted in a homogeneous population of cells with numerous long microvilli, large ruffles, and blebs over the whole surface. The cells retained the same altered surface structure until tumorigenicity after reimplantation into the syngeneic host was first observed (approximately 273 days). Surface alterations characteristic of the neoplastic cells were thus observable more than 100 days before the cells became tumorigenic.

Animals↗
PubMed1977

Phenotypic properties of neoplastic cell lines developed from fetal rat brain cells in culture after exposure to ethylnitrosourea in vivo.

We have recently reported that fetal BD IX-rat brain cells (FBC), transferred to long-term culture after a transplacental pulse of EtNU on the 18th day of gestation, undergo neoplastic transformation in vitro ("BT-cell lines"). Tumors developed upon s.c. reimplantation of BT-cells into baby BD IX-rats, appeared histologically as neurinoma-, glioma- or glioblastoma-like, and frequently as pleiomorphic neoplasms. In spite of a more atypic cellular morphology, these tumors grossly resembled the different types of neuroectodermal rat neoplasms induced by EtNU in vivo. Like the neoplastic cell culture lines derived from EtNU-induced, neuroectodermal BD IX-rat tumors ("V-cell lines"), the BT-lines contained multipolar glia-like cells, but also flat cells with fewer and shorter cytoplasmic processes, and occasionally giant cells. Both the V- and BT-lines showed different levels of aneuploidy. They contained multiple subpopulations of cells, as reflected, e.g., by plurimodal pulse-cytophotometric DNA distributions. All lines contained, to varying degrees, the nervous system-specific protein S-100, a "marker" not yet expressed in FBC. There was no indication of more than borderline neurotransmitter activity, suggesting that proliferating (precursor) cells of glial lineages may preferentially undergo malignant transformation after exposure to EtNU during this stage of brain development.

Animals↗
PubMed1977

Surface markers in non-phagocytic hairy cell leukemia.

By phase contrast and scanning electron microscopy hairy cells were demonstrated in the peripheral blood, bone marrow and spleen of a patient with hairy cell leukemia. Immunofluorescent tests revealed IgD on the surface of 92 per cent, IgG, on 76 per cent, IgM on 12 per cent and albumin on 95 per cent of the cells from the spleen. After overnight culture, IgG and albumin were detected on 4 and 6 per cent of the cells respectively, while the number of IgD and IgM positive cells persisted. Fifty-two per cent of the hairy cells formed rosettes with erythrocytes sensitized with IgG antibodies (EA), whereas 70 per cent formed rosettes after trypsin and protease treatment. The hairy cells did not form rosettes with erythrocytes sensitized with IgM antibodies and complement (EAC), or with sheep and mouse erythrocytes. Cryostat sections of spleen strongly adsorbed EA, whereas no adsorption occurred with EAC or sheep erythrocytes. The hairy cells did not phagocytize latex particles or ingest a strain on yellow staphylococci. The results suggest that hairy cells from this patient probably were of B-lymphocyte origin.

Bone Marrow↗
PubMedDate not supplied

Transformation of human kidney epithelial cells to tumorigenicity by nickel(II) and V-HA-RAS oncogene.

Nickel is a toxic metal of environmental concern that has been found to be carcinogenic in man and animals. Primary human kidney (NHKE) cells were immortalized or rescued from senescence after exposure to NiSO4. The cell lines (IHKE) displayed abnormal karyotype and anchorage independent growth was observed. However, none of the IHKE cells produced tumor upon injection into athymic nude mice. Transfer of the v-Ha-ras oncogene into IHKE cells induced conversion of the immortalized cells into cell lines (THKE) that were tumorigenic when transplanted into athymic nude mice. Ha-ras DNA was present in the transformed cell lines and expressed at high level.

Animals↗
PubMedDate not supplied

Growth of human lung adenocarcinoma in nude mice is influenced by various types of dietary fat and vitamin E.

Studies have shown effects of dietary lipids on carcinogenesis and tumour progression. Different mechanisms for the inhibitory effect of n-3 fatty acids (FA) have been proposed. The inhibition of the growth of subcutaneously transplanted A427 lung adenocarcinoma cells in athymic nude mice may occur due to an increased level of lipid peroxidation products and is the object of this study. The nude mice were fed diets supplemented with corn oil (CO), olive oil (OO) or K85, a mixture of ethyl esters of n-3 FAs, mainly eicosapentaenoic acid (EPA, 20:5, n-3) and docosahexaenoic acid (DHA, 22:6, n-3). Tumours of the n-3 FA group showed reduced growth. Peroxidation products measured by the thiobarbituric acid reactive substances (TBARS) test showed higher levels in tumours from n-3 FA fed mice than in the other diet groups. The growth inhibitory effects and the elevated level of TBARS in the n-3 FA diet group were counteracted by vitamin E supplement in the diet. Cu/Zn-superoxide dismutase (SOD) activity in liver did not differ greatly among the diet groups. The Ki-67 labelling index (LI), indicating cell proliferation rate was significantly lower in the K85 diet group compared to the other diet groups.

Adenocarcinoma↗