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Biomedical subjects

L C Andersson

Publications and source records attributed to L C Andersson.

At least 109 records · Page 6Linked to original sources
PubMed1989

The impact of 25 years of iodine prophylaxis on the adult thyroid weight in Finland.

The effect of iodine prophylaxis on endemic goiter was studied in an adult Finnish population by comparing autopsy records from 1959 and 1984. In the 1950's the iodine intake calculated both from urinary excretion of stable iodine and from food analysis data was 50-70 micrograms per day the intake being lower in the main endemic area in the eastern part of the country. The use of iodized salt raised these figures only by 15 micrograms per day. At the beginning of the 1980's the iodine intake calculated in the same way was around 300 micrograms per day all over the country. Initially 696 records from 1959 and 525 from 1984 were analyzed. Excluded were cases with primary or secondary malignant thyroid tumors, autopsies with incompletely recorded thyroid weight, and autopsies from patients submitted to pituitary or thyroid surgery or radiation therapy. Finally, 318 cases from 1959 and 478 from 1984 were accepted. A significant decrease in thyroid weight from a mean of 44 to a mean of 34 g was observed. The difference between the two populations was most marked in the age groups below 45 yr. In these age groups the mean thyroid weight was about 20-27 g which can be regarded as normal. In the age groups over 75 years there were no significant differences. These data indicate that the iodine prophylaxis gradually eradicates the endemic goiter in Finland but that it requires still some 25-35 yr before it has disappeared also in the oldest age groups.

Adolescent↗
PubMed1989

Interleukin-2 induces a rapid increase in ornithine decarboxylase mRNA in a cloned murine T lymphocytic cell line.

We recently observed a 25-fold increase in the activity of ornithine decarboxylase (ODC) 6 h after treatment of G1-synchronized CTLL-2 cells with interleukin-2 (IL-2). Here we show that the ODC mRNA content increased in parallel with the ODC activity during the first hours of stimulation with IL-2, resulting in a 25-fold increase at 6 h. Between 6 and 24 h the ODC mRNA content continued to increase steadily up to 50-fold, even after the ODC activity had returned to low basal levels. In the case of density-arrested CTLL-2 cells deprived of IL-2 for 16 h, the IL-2-mediated increase in ODC mRNA was 2-fold at 1 h and 5-fold at 8 h, irrespective of the capability of the cells to resume their cycle. There was no marked increase in the rate of transcription of the ODC gene, at least during the first 2 h of stimulation with IL-2. These findings suggest that the regulation of the ODC activity by IL-2 is a primary event in IL-2-induced cell proliferation and occurs at the post-transcriptional level, possibly by stabilizing the ODC mRNA and affecting the efficiency of translation of the messenger.

Animals↗
PubMed1989

Interleukin-2 regulates the activity of ornithine decarboxylase in a cloned murine T lymphocytic cell line: evidence for a protein kinase C-dependent pathway.

The role of protein kinase C (PKC) in the regulation of ornithine decarboxylase (ODC) activity during interleukin-2 (IL-2)-dependent cell growth was investigated. A large biphasic increase in the activity of ODC was observed after treatment of IL-2-deprived CTLL-2 cells with recombinant human IL-2 (rec IL-2). The PKC activators phorbol 12-myristate 13-acetate (PMA) and 4 beta-phorbol 12,13-didecanoate (4 beta-PDD), but not the inactive analog 4 alpha-PDD, induced ODC activity in exponentially growing cultures. Unlike IL-2, however, phorbol esters were poor inducers of IL-2-depleted cultures. H-7, a potent inhibitor of PKC and cyclic nucleotide-dependent protein kinases (CN-PK), suppressed the IL-2-induced ODC activity, while HA1004, a more potent inhibitor of CN-PK than of PKC, had opposite effects depending on its concentration. The results suggest that activation of PKC is involved in but is not the sole mechanism for the induction of ODC by rec IL-2. At concentrations which suppressed the induction of ODC activity by IL-2, H-7 inhibited DNA synthesis and HA1004 did not.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1989

Antibodies against gastrointestinal carcinoid tumors in IDDM.

In this study, 92% of patients' serums known to contain antibodies against islet cells, including the Juvenile Diabetes Foundation provisional reference serum, had antibodies reacting with gastrointestinal carcinoid tumors. Twelve percent of the control serums from healthy individuals bound to carcinoid cells, and 2% bound to islet cells. Seventy-five percent of the children with newly diagnosed insulin-dependent diabetes mellitus had carcinoid tumor antibodies, and 83% had islet cell antibodies. These findings suggest that antigenic determinants are shared between endocrine cells of islets of Langerhans and neuroendocrine tumors of the same embryological derivation. Carcinoid tumors may not only provide an alternative source for islet cell antibody assays but also supply material for isolation of antigens possibly involved in the immunopathogenesis of diabetes.

Adult↗
PubMed1988

Mechanism of anaemia in rheumatoid arthritis: demonstration of raised interleukin 1 beta concentrations in anaemic patients and of interleukin 1 mediated suppression of normal erythropoiesis and proliferation of human erythroleukaemia (HEL) cells in vitro.

The pathogenesis of the anaemia associated with rheumatoid disease is unclear. It has previously been shown that the degree of the anaemia correlates with the severity of the inflammatory disease and that serum from patients with arthritis inhibits erythropoiesis. This study was designed to examine whether interleukin 1 could be a mediator of the anaemia in rheumatoid arthritis. Radioimmunoassay of interleukin 1 beta in serum showed that patients with rheumatoid arthritis and associated anaemia had significantly higher interleukin 1 beta concentrations than patients with rheumatoid arthritis without anaemia. Pure recombinant human interleukin 1 alpha and interleukin 1 beta, in concentration ranges similar to those found in the arthritic patients, markedly suppressed the colony formation of the erythroid, but not the granulocyte-macrophage progenitor cells in cultures of normal bone marrow. Natural human interleukin 1 and recombinant interleukin 1 beta, but not interleukin 1 alpha, suppressed in a dose dependent manner the proliferation of the human erythroleukaemia cell line (HEL) in cultures, suggesting that the interleukin 1 effect is a direct one. The results show that interleukin 1 is a humoral inhibitor of erythropoiesis and suggests that interleukin 1 is involved in the development of anaemia in association with rheumatoid arthritis.

Adult↗
PubMed1988

Enhanced expression of transforming growth factor beta during megakaryoblastic differentiation of K562 leukemia cells.

Platelet alpha granules contain several growth factors such as the transforming growth factor beta (TGF-beta) that are released during blood clotting and are thought to participate in the repair of tissue injury; however, the site of synthesis of platelet TGF-beta has not been demonstrated. We studied TGF-beta expression during megakaryoblastic differentiation of the chronic myeloid leukemia cell line K562 in vitro. These cells have mainly erythroid characteristics but acquire several megakaryoblastic properties when treated with the phorbol diester 12-0-tetradecanoyl-13-phorbolacetate (TPA). During four subsequent days of megakaryoblastic differentiation the amount of the 2.5-kilobase (kb) TGF-beta mRNA increased about eightfold, and a novel 2.3-kb mRNA species was induced in the K562 cells. This occurred concomitantly with distinct induction patterns of platelet-derived growth factor A (PDGF-A) and c-sis (PDGF-B chain) RNAs and several platelet antigens. The expression of erythroid markers such as glycophorin A decreased. Culture media of TPA-differentiated K562 cells also contained TGF-beta polypeptides as shown by a sensitive radioreceptor assay and by immunoprecipitation after metabolic labeling of the cells. These polypeptides were not seen in culture media from dimethyl sulfoxide- or sodium butyrate-treated cells. Unlike in several other cells, exogenously added TGF-beta 1 or 2 affected neither TGF-beta nor PDGF RNA expression in K562 cells.

Cell Line↗
PubMed1987

Growth signal transduction: rapid activation of covalently bound ornithine decarboxylase during phosphatidylinositol breakdown.

We have previously shown that treatment of T lymphocytes with mitogenic ligands induces a rapid activation of ornithine decarboxylase (ODC) through a mechanism that is independent of protein synthesis but requires energy and an intact cytoskeleton. Here we show by immunoprecipitation experiments and by chemical analyses that ODC is covalently linked to the cell membrane by inositol. Treatment of sonicated cells with a phosphatidylinositol-specific phospholipase C from B. thuringiensis caused a rapid 3-fold increase in ODC activity. Similar treatment of intact cells had no effect, suggesting that the ODC is attached to the cytoplasmic surface of the membrane. We conclude that ODC release and activation occur by a novel mechanism involving phosphatidylinositol breakdown following ligand-receptor interaction.

Animals↗
PubMed1987

Cultured mammary carcinoma cells contain gonadotropin-releasing hormone-like immunoreactivity, GnRH binding sites and chorionic gonadotropin.

Immunoperoxidase staining and radioimmunoassay were used to identify gonadotropin-releasing hormone (GnRH) and chorionic gonadotropin (hCG) in 4 mammary carcinoma cell lines. GnRH-like immunoreactivity was found in all cell lines; 2 lines also contained hCG. Binding of a GnRH agonist was demonstrated by radioreceptor assay in cultured mammary carcinoma cells. In cell column perfusion of the same cells, exogenous GnRH did not stimulate release of hCG.

Binding Sites↗
PubMed1987

Induction of platelet-derived growth factor gene expression during megakaryoblastic and monocytic differentiation of human leukemia cell lines.

Platelet-derived growth factor (PDGF) is one of the most important polypeptide growth factors in human serum. It is composed of two polypeptide chains linked by disulfide bonds. The B-chain is encoded by the c-sis proto-oncogene, which is expressed in several malignant and non-malignant cells including K562 cells differentiating towards megakaryoblasts. Expression of the A-chain has been reported to occur in human solid tumor cell lines independently of c-sis expression. We report here the non-coordinate expression of the A- and B-chains in human leukemia cell lines. The PDGF-A and B-chain (c-sis) RNA expression as well as secretion of PDGF polypeptides are induced in the K562 cell line upon induction of megakaryoblastic differentiation with 12-O-tetradecanoyl phorbol-13-acetate (TPA) whereas erythroid differentiation induced with sodium butyrate is accompanied by c-sis expression only. Simultaneously with megakaryoblastic differentiation the RNA level for another platelet protein, the transforming growth factor-beta was also increased, but in a complex manner. The promyelocytic leukemia cell line HL-60 does not express PDGF-A RNA, whereas the promonocytic cell line U937 does. Preferential induction of the A-chain RNA is obtained in both cell lines after treatment with TPA which causes monocytic differentiation. PDGF-A expression in HL-60 cells is also observed after treatment with the tumor necrosis factor-alpha but granulocytic differentiation of HL-60 cells induced with dimethyl sulfoxide or the granulocyte colony-stimulating factor is not associated with PDGF gene expression.

Cell Differentiation↗
PubMed1987

Identification of glycoproteins expressing tumour-associated PNA-binding sites in colorectal carcinomas by SDS-GEL electrophoresis and PNA-labelling.

Many tumour-specific antigens in gastrointestinal cancers have carbohydrate immuno-determinants. These epitopes can be identified by lectins and monoclonal antibodies. By using fluorescein-isothiocyanate (FITC)-conjugated peanut agglutinin (PNA) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) we have investigated glycoproteins carrying altered carbohydrate epitopes in normal and carcinomatous human colorectal mucosa. In normal mucosa PNA stained goblet cell glycoconjugates in the supranuclear (Golgi) distribution. After neuraminidase pretreatment PNA stained actual mucin goblet itself at all levels of the crypts. Colorectal carcinomas displayed a strong and direct binding of PNA to apical cell membranes of carcinomatous cells and intraluminal secretions. Analysis of the glycoproteins by SDS-PAGE and PNA-labelling revealed four carcinoma-associated glycoproteins (26kD, 32kD, 35kD and 50kD). In addition, four glycoproteins (29kD, 30kD, 33kD and 36kD) common to normal and carcinomatous colorectal mucosa could be identified. All of these glycoproteins differed in their molecular weight from those in red cell controls which bind PNA only after desialylation. The study shows that the expression of PNA-binding sites in colorectal carcinomas signifies a cancer-associated carbohydrate alteration. Four carcinoma-associated glycoprotein antigens could be detected by this lectin. The antigens we have identified might be useful in the isolation and purification of more selective reagents for the serologic detection of colorectal cancer.

Antigens, Neoplasm↗
PubMed1987

Induction of cytotoxic capacity by recombinant gamma interferon in human myelomonocytic leukaemia cell lines.

We have investigated the ability of human recombinant gamma interferon (IFN-gamma) to induce functional differentiation in three human myelomonocytic cell lines U937, RC2A, and ML-2. Treatment with IFN-gamma induced natural killer (NK) cell like cytotoxicity against K-562 cells in ML-2 and RC2A but not in U937. U937 and RC2A displayed a spontaneous antibody-dependent cell-mediated cytotoxicity (ADCC), which against nucleated target cells was significantly increased in U937 but not in RC2A after treatment with IFN-gamma. ML-2 did not display ADCC against nucleated targets either before or after IFN-gamma treatment, but lysed efficiently antibody-coated erythrocytes. All three cell lines displayed enhanced ADCC against erythrocytes after IFN-gamma treatment. Spontaneous phagocytosis of erythrocytes was seen in U937, and this was enhanced by IFN-gamma treatment, while ML-2 and RC2A were phagocytically inactive before and after treatment with IFN-gamma. The differentiated functions induced by IFN-gamma treatment in this panel of phenotypically closely related cell lines offers an interesting model for further studies on the IFN-gamma regulated gene expression. Moreover, the increased cytolytic capacity after exposure to IFN-gamma might have implications on the use of IFN-gamma for treatment of myelomonocytic malignancies. In such cases, IFN-gamma might even increase the aggressiveness of the tumour.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1987

The gene for the Leu-M2 (Mac-120) antigen is located on human chromosome 11.

Leu-M2 (Mac-120) antigen is a cell-surface marker present on a subpopulation of human blood monocytes and platelets. Its expression on monocytes and macrophages is necessary for their ability to present antigen to T lymphocytes. Only Leu-M2+ cells display the human Ia-like determinant, HLA-DS, which seems important in antigen presentation and stimulation in the autologous MLR. Expression of the Leu-M2/Mac-120 antigen was studied by indirect immunofluorescence analysis and flow cytofluorometry in mouse-human somatic cell hybrids segregating human chromosomes. In the mouse-human hybrid clones, expression of the Leu-M2/Mac-120 antigen was dependent on the presence of human chromosome 11. This was verified by fluorescence-activated cell sorting of heterogeneous hybrid cell populations into antigen-positive and-negative fractions. The Leu-M2 antigen co-segregated with chromosome 11. The gene controlling the expression of the Leu-M2/Mac-120 antigen thus is assigned to human chromosome 11.

Antigens, Differentiation, Myelomonocytic↗
PubMed1987

Transduction of mitogenic signals in T lymphocytes. Role of inositol phospholipids for the rapid activation of ornithine decarboxylase.

Treatment of human T lymphocytes with mitogenic ligands, such as concanavalin A (Con A), induces a rapid activation of the enzyme ornithine decarboxylase (ODC). This activation occurs within minutes and is completely inhibited when the cells are treated with 1 mM Li+ (in an inositol-free medium) prior to stimulation with Con A. In the presence of 1 mM myo-inositol Li+ has no effect on the Con A-induced activation of ODC. To elucidate why inositol is needed for the mitogen-induced activation of ODC in T lymphocytes, we tested the ability of different inositol metabolites to reverse the inhibitory effect of Li+. Here we report that inositol phospholipids, in addition to inositol, reverse the Li+-induced inhibition of ODC activation, while all other inositol derivatives tested were ineffective. This indicates that Li+ does not block the activation of ODC by inhibiting the generation of inositol phosphates, but rather by a mechanism which is circumvented if inositol phospholipids are added. The molecular mechanisms involved in the rapid activation of ODC by mitogens in human T lymphocytes apparently require inositol phospholipids, but are not directly mediated by inositol-1,4,5-trisphosphate (IP3) alone, diacylglycerol alone, or other inositol phosphates.

Enzyme Activation↗
PubMed1987

Oncoplacental protein SP1--a constitutive and inducible late differentiation marker of the human myelomonocytic lineage.

The oncoplacental protein SP1 is found in large quantities in human placenta, amniotic fluid, and pregnancy serum. Low levels have been reported in association with malignancy but also in healthy nonpregnant individuals. By indirect immunofluorescence, fluorescence-activated cell sorting, and immunoprecipitation we here demonstrate the presence of SP1 both on the surface and in the cytoplasm of human granulocytes but not in earlier myeloid progenitor cells in bone marrow. Lymphocytes did not contain the protein, and only trace amounts could be found in the cytoplasm of blood monocytes. A major glycoprotein with an apparent mol wt of 90,000 was obtained by immunoprecipitation of surface-labeled granulocytes. Cultivated blood monocytes, while adhering to surfaces or forming multinuclear giant cells, displayed a strong membrane and cytoplasmic expression of SP1. Treatment of the myeloid leukemia cell line ML-2 with tetraphorbol acetate (TPA) strongly induced SP1 in the membrane and cytoplasm as revealed by immunofluorescence and polyacrylamide gel electrophoresis (PAGE) of immunoprecipitates from lysates of surface radiolabeled cells. The induction of synthesis of SP1 in TPA-treated cells was confirmed by immunoprecipitation from lysates of cells metabolically labeled with 35S-methionine. Human lymphoblastoid and erythroleukemic cell lines did not express SP1 either before or after induced differentiation. Thus SP1 provides a late differentiation marker for the myelomonocytic lineage and is strongly induced during macrophage differentiation or by TPA treatment of ML-2 cells.

Cell Differentiation↗