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J Hammerstrøm

Publications and source records attributed to J Hammerstrøm.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Acquired von Willebrand's disease].

We describe a patient with acquired von Willebrand's disease and Waldenström's macroglobulinemia. He suffered from an acquired tendency to bleed. The laboratory findings were identical to those of congenital von Willebrand's disease. The acquired form of this bleeding disorder is seen in association with immunologically active B cell lymphomas, certain other malignant tumours, and autoimmune diseases. The incidence and prevalence are unknown, but this disorder is probably uncommon. We discuss possible pathogenetic mechanisms. Acquired von Willebrand's disease should be considered in patients with an acquired tendency to bleed, especially if the patient also has a lymphoproliferative, neoplastic, or autoimmune disease.

Aged↗
PubMed1992

[New therapeutic possibilities for acquired clonal blood diseases and myelodysplasia].

Examples of patients are used as a basis for discussing the treatment of severe aplastic anaemia with clonal chromosomal aberrations in haematopoietic cells, the aplastic form of paroxysmal nocturnal haemoglobinuria and myelodysplasia, with allogeneic bone marrow transplantation. Transplantation with marrow from an HLA-identical sibling donor has curative potential in selected patients with these disorders. The procedure should preferably be carried out before the patients have received massive treatment for the complications of marrow failure. The use of matched unrelated bone marrow donors is still at the investigation stage.

Adult↗
PubMed1992

[Bone marrow aspiration. Use and benefits].

Bone marrow aspiration is an old and well-established test procedure, the use of which may rest more on diagnostic tradition than on scientific documentation. Its use was evaluated in a Norwegian regional hospital by registering indication, presence of pathology and clinical "utility" judged from a given definition, in 200 reports on bone marrow aspiration. The result was pathological in 53%, and judged to be clinically useful in 61% of the tests. The diagnostic yield was highest for indications related to bone marrow function, and low for unspecific indications such as fever of unknown origin and elevated SR without M-component. The large number of results with pathological findings that are judged to be clinically useful raise the question of whether use of this test should be increased.

Biopsy, Needle↗
PubMed1992

Spurious platelet counts in acute leukaemia with DIC due to cell fragmentation.

Automated platelet counts in a patient with newly diagnosed AML M5 with extreme leukocytosis were reported as 129, 166 and 121 x 10(9)/1. Routine blood films showed a corresponding number of platelet-sized particles, judged to be platelets. The patient was treated for DIC with low-dose heparin infusion. Platelet transfusions were not given initially. The patient died 14 h after admission from intracerebral haematoma. The origin of the platelet-sized particles seen in routine stained blood films was examined by cytochemical and immunological staining for peroxidase, non-specific esterase, CD 13 and CD 33. About 1/3 of the fragments had the same staining characteristics as the leukaemia cells, indicating leukaemia cell origin. Staining for platelet-specific antigen GpIIIa was positive only in 4% of the platelet-sized fragments, with a calculated true platelet count of 4 x 10(9)/1. The presence of cell fragments masquerading as platelets should be suspected in leukaemia patients with bleeding symptoms and normal or near normal platelet counts.

Acute Disease↗
PubMed1987

In vitro cultured human monocytes release fibroblast proliferation factor(s) different from interleukin 1.

Human monocytes cultured in vitro released factors with growth stimulatory effect upon human dermal fibroblasts. Monocytes in RPMI 1640 released a growth enhancing activity in nearly constant amounts during in vitro differentiation to macrophage-like cells. The growth stimulatory effect mediated by supernatants was reduced when lipopolysaccharide (LPS) or opsonized zymosan particles (OpZ) were added to monocytes during the first 5 days of in vitro culture, thereafter reaching similar levels. The release of interleukin 1 (IL-1) from monocytes was restricted to the first 2 days of culture. IL-1 production by unstimulated monocytes was negligible, while LPS induced a high release of IL-1 from monocytes. A rabbit antibody against human IL-1 abolished the IL-1 activity of the monocyte supernatants as assessed in a mouse thymocyte proliferation assay, but caused only a small reduction of the fibroblast proliferation activity. Thus, the fibroblast growth stimulatory activity mediated by monocytes was caused by factor(s) in addition to IL-1.

Cell Differentiation↗
PubMed1986

Human monocyte cytotoxic factor mediates cytolysis of WEHI 164 cells.

Human monocytes can be activated to release a 40,000-Da cytostatic protein factor (CF). In this report we have investigated the cytolytic activity of CF on WEHI 164 cells which are sensitive to monocyte-mediated cytolysis. Monocyte supernatants containing CF induced cytolysis of murine WEHI 164 sarcoma cells, as determined in a 51Cr-release assay. Preincubation of WEHI 164 cells with actinomycin D enhanced cytolysis induced by supernatants containing CF, suggesting that CF may be involved in drug-dependent cellular cytotoxicity. The cytolytic activity was profoundly inhibited by a rabbit antiserum raised against purified CF, indicating that the cytolytic activity in the supernatants was in fact mediated by CF. These results indicate that CF may be an important effector molecule in monocyte-mediated cytostatic and cytolytic reactions.

Adjuvants, Immunologic↗
PubMed1986

Role of monocyte cytotoxic factor in cytolysis of actinomycin D-treated WEHI 164 cells mediated by freshly isolated human adherent mononuclear blood cells.

The role of the monocyte cytotoxic factor (CF) in cytolysis of untreated and actinomycin D (Act D)-treated WEHI 164 cells by freshly isolated human adherent mononuclear cells has been investigated in this study. Murine WEHI 164 cells were used as target cells because of their sensitivity to lysis mediated by monocytes and their resistance to natural killer cells. Monocytes as well as monocyte supernatants mediated cytolysis of WEHI 164 cells. Cytolysis was enhanced by Act D treatment of target cells. The addition of lipopolysaccharide to monocytes accelerated the progression of cytolysis of Act D-treated WEHI 164 cells mediated by monocytes. A polyclonal rabbit antiserum against CF inhibited the cytolytic activity of monocytes and monocyte supernatants against untreated as well as Act D-treated WEHI 164 cells. At low effector:target ratios, the cytolysis was totally abrogated by CF antiserum. Depletion of natural killer cells from adherent cells by the monoclonal antibody Leu 11b and rabbit complement did not reduce cytolysis of Act D-treated WEHI 164 cells. Immunofluorescence microscopy revealed that CF antiserum stained the plasma membrane of freshly isolated monocytes, suggesting that CF is a membrane-associated molecule. Our data indicate that CF is an important effector molecule in cytolysis mediated by freshly isolated monocytes against untreated and Act D-treated WEHI 164 cells.

Animals↗
PubMed1983

Soluble cytostatic factor(s) released from human monocytes. II. Effects on target cell kinetics.

Human monocytes release a stable cytostatic factor during in vitro culture after stimulation with lymphokine and endotoxin. The cell cycle time of synchronized NHIK 3025 cells increased from 20.3 to 23.2 h in the first cell cycle when the target cells were exposed to the factor during the whole cell cycle. In exponentially growing NHIK 3025 cell cultures the cell doubling time increased from 18.9 h to 23.1 h under continuous factor exposure for 70 h. These cells regained normal cell division rate when fresh culture medium replaced the cytostatic factor. Continuous exposure to the cytostatic factor for 96 h increased the cell doubling time of asynchronous K-562 cells from 19.7 to 31.8 h. The target cell DNA synthesis, evaluated by thymidine incorporation, was markedly depressed after culture with the factor for 24 h, and this depression was detectable already within 4 h of culture. The factor showed no cytolytic effect on the two cell lines tested. The cytostatic factor influenced the cell cycle distribution of both target cells tested, since cell cycle analysis by DNA flow cytometry demonstrated a reversible inhibition of factor-exposed NHIK 3025 cells in G1- and early S-phase, whereas K-562 cells accumulated in G1-phase.

Cell Cycle↗
PubMed1983

Human monocyte-mediated antibody dependent cytotoxicity to K-562 cells: an electron microscopic study.

Human monocyte-mediated antibody dependent cytotoxicity (ADCC) to K-562 cells has been examined using 51Cr-release assays and electron microscopy. Non-activated monocytes lysed antibody-coated K-562 cells rapidly, the observed lysis reaching a constant level of 28% after 6 h of co-culture. Lymphokine-activated monocytes mediated ADCC with a similar time course but with higher cytolysis level (42%) compared to non-activated monocytes. The cytolysis was dependent on the amount of antibody on the K-562 cells and on the number of effector cells present in the assay. Scanning electron microscopy revealed that sensitized target cells in contact with monocytes lost their microvilli. Lysis was probably extracellular, but a small number of completely engulfed intact target cells were observed. Lymphokine-activation of the monocytes led to a dissociation of the phagocytic and cytotoxic activity, indicating that phagocytosis is not directly involved in ADCC. Thin section- and freeze-fracture electron microscopy of the contact area between effector and target cells revealed no membrane specializations. The cells were always separated by a gap of 20-30 nm interrupted by characteristic invaginations in the opposing plasma membranes.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1982

Dissociation between tumour cell cytostatic and immuno-suppressive capacity of human monocytes activated with lymphokines.

Activation of monocytes with lymphokines from BCG-stimulated lymphocytes increased the capacity to inhibit DNA-synthesis in a tumour cell line (NHIK 3025) at all stages of monocyte maturation in vitro. However, the capacity of monocytes to suppress DNA-synthesis in mixed lymphocyte cultures (MLC) was reduced, indicating a dissociation of the immuno-suppressive and tumour cell cytostatic functions of lymphokine-activated monocytes. Supernatants of lymphokine-activated monocytes inhibited DNA synthesis in the tumour cell line, but not in MLC. Monocytes from donors with a strong tuberculin reaction produced supernatants with a stronger cytostatic activity than monocytes from donors with a weak tuberculin reaction. By in vitro maturation, even the later monocytes acquired ability to produce supernatants that were strongly inhibitory to tumour cells.

Cell Division↗
PubMed1982

Human monocyte mediated cytotoxicity to K-562 cells: a freeze-fracture-, scanning- and thin section electron microscopic study.

The structural features of "natural"human monocyte-mediated cytotoxicity towards K-562 leukemia cells in vitro have been examined. Human monocytes bound K-562 cells firmly and mediated a slow cytolysis of the leukemia cells. Monocyte binding of target cells was shown to be trypsin sensitive. Freeze-fracture and thin section electron microscopy revealed that effector and target cells were separated by a irregular space larger than 20 nm. There was no evidence for the involvement of specialized membrane junctions or organelle transfer between monocytes and target cells. Scanning electron microscopy revealed that K-562 cells bound to monocytes progressively lost their microvilli. This process started in the membrane areas close to the effector-target cell interaction. The results suggest that binding of target cells by monocytes followed by action of short-range soluble cytotoxic mediators may be the mechanism for the monocyte-mediated cytotoxicity towards K-562 cells.

Animals↗
PubMed1982

Physicochemical characterization of cytostatic factors released from human monocytes.

Cultured human monocytes released cytostatic activity upon in vitro activation with lymphokines and lipopolysaccharide. This activity was mainly due to the presence of two different cytostatic factors, termed CstF I and II, which were separated by ion-exchange chromatography. At neutral pH, CstF I bound to the weak anion exchanger DEAE-Sephacel but not to the weak cation exchanger CM-Sepharose, whereas CstF II bound to CM-Sepharose but not to DEAE-Sephacel. The molecular weights of CstF I and II as determined by gel filtration were 55,000 and 40,000, respectively. Upon chromatofocusing, CstF I behaved as if it had an isoelectric point of 5.3. Neither CstF I nor CstF II bound specifically to concanavalin A-Sepharose, indicating the absence of carbohydrate residues containing alpha-D-mannopyranosyl, alpha-D-glucopyranosyl, or sterically related components. Both factors were susceptible to inactivation by proteinase K, demonstrating their protein nature. CstF II was purified more than 3,000-fold upon chromatography on CM-Sepharose and Sephacryl S-200. Ion-exchange chromatography and chromatofocusing of CstF I removed 97% of the proteins in the monocyte supernatant, but only 15% of the activity was recovered, resulting in a fivefold purification of CstF I.

Cell Division↗
PubMed1981

Human adherent mononuclear blood cells: cytolytic and cytostatic activity and characterization of effector cells during in vitro culture.

Using a methyl-3H-thymidine release assay, the cytolytic activity of human adherent mononuclear blood cells (AC) against three transformed human tumour cell lines of mesenchymal (U-205), epithelial (NHIK 3025) and hematogenous (K-562) origin was compared to the activity against non-transformed skin fibroblasts (U-2S) and mesothelial cells (meso). Only transformed target cells were affected by the spontaneous cytolytic activity of normal AC tested after 0, 4 or 8 days of in vitro culture. Lymphokine-activated 4-days old AC also preferentially lysed transformed target cells, but low levels of lysis of non-transformed target cells were observed at high effector cell densities. Freshly isolated AC were spontaneously cytostatic to K-562, but not to NHIK 3025 cells, while differentiated AC cultured for 8 days were cytostatic to both cell lines. Lymphocyte-like cells comprised up to 10% of freshly isolated AC, and most of these lymphocytes seemed to be non-T-cells as evaluated by alpha-naphthyl-esterase (ANAE) staining. Most of these cells detached during the first 24 h of in vitro culture, and the fraction of AC expressing monocyte markers (diffuse ANAE reactivity, interaction with ox erythrocytes coated with IgG of IgM + complement, interaction with Candida albicans) increased to nearly 100% after 4-8 days of in vitro culture. Thus, the effector cells expressing spontaneous cytolytic activity in this system have monocyte characteristics after 1 day of in vitro culture. However, contribution of adherent non-monocytic cells to the cytotoxicity observed during the first 24 hours of culture can not be ruled out.

Cell Line↗
PubMed1980

Structure and function of human effusion macrophages from patients with malignant and benign disease. 1. Isolation, morphology, proliferation and phagocytosis.

The inflammatory cell composition of pleural or ascitic effusion fluids from 13 patients with malignant disease and 8 patients with benign disease was analyzed. The macrophage content in the effusions was 4.1 x 10(5) +/- 1.3 cells/ml (mean +/- SEM), with large variation (range 0.1 - 27.9 x 10(5) cells/ml) among patients. Major blood cell contamination was excluded by the finding of low red blood cell/nucleated cell ratios in the effusions. Effusion macrophages were isolated by Ficoll/Isopaque centrifugation and plastic adherence. Monolayers of > 90% alpha-napthyl-esterase-positive and/or phagocytic cells were produced in most experiments. Adherent effusion cells incorporated low amounts of methyl-3H-thymidine (methyl-3H-TdR). Most cells in DNA-synthesis were removed by trypsin, indicating that they were not macrophages. Lymphokine supernatants induced increased methyl-3H-TdR incorporation in adherent cells in 3 of 8 experiments, and microscopic proliferation of phagocytic cells was evident in one experiment. Endotoxin and Corynebacterium parvum reduced adherent cell DNA-synthesis slightly. Effusion macrophages ingested more 125I-labelled Candida albicans than peripheral blood monocytes. The ability to degrade ingested Candida and the cell adherence after phagocytosis were found to be greater in the macrophages than in monocytes. Effusion macrophages with monocyte-like, undifferentiated appearance differentiated like monocytes in vitro. Further in vitro differentiation of macrophages with more differentiated appearance often seemed to be blocked, the cells dying gradually after 4-8 days in vitro.

Ascitic Fluid↗
PubMed1980

Structure and function of human effusion macrophages from patients with malignant and benign disease. 2. In vitro cytostatic and cytolytic effect on human tumour cell lines.

Human effusion macrophages isolated from the pleural or ascitic effusions of 14 patients with malignant or benign disease usually inhibited methyl-3H-thymidine incorporation in an adherent human tumour cell line (NHIK 3025) when the macrophages were challenged with target cells immediately after isolation. The cytostatic activity disappeared when the macrophages were cultured for 18 hours in vitro before target cell challenge. The presence of endotoxin (LPS) or Corynebacterium parvum (Cp) during the macrophage-target cell interaction induced a small enhancement of the macrophage-mediated cytostatic activity. Preincubation of macrophages with Cp or Cp-induced lymphokine supernatants for 2-18 hours before target cell challenge induced increased cytostatic activity in the macrophage cultures. Adherent (NHIK 3025) or non-adherent (K-562) human tumour cells prelabelled with methyl-3H-thymidine, when added to freshly isolated macrophages, were lysed in a slowly progressive manner. The cytolytic activity to K-562 cells was enhanced by increasing macrophage density in the cultures, and by incubating the macrophages for 2 hours with lymphokine supernatants before target cell challenge. Morphological observations indicated that K-562 cells adhered to macrophage membranes, with lysis proceeding extracellularily.

Ascitic Fluid↗