Search PubMed⌕ Search

Biomedical subjects

K Nilsson

Publications and source records attributed to K Nilsson.

At least 397 records · Page 22Linked to original sources

In search of alpha 1-microglobulin on the lymphocyte surface.

alpha 1-Microglobulin was found by immunofluorescence not to be associated with human lymphoid and nonlymphoid cell lines. No accumulation of alpha 1-microglobulin was detected in culture media of these cell lines. A weak membrane fluorescence with anti-alpha 1-microglobulin on peripheral lymphocytes could not be blocked by the purified protein. No release of alpha 1-microglobulin into the growth medium was seen by normal cultured leukocytes. Treatment of normal lymphocytes, erythrocytes, and various cell lines with solubilization techniques did not yield any alpha 1-microglobulin. alpha 1-Microglobulin and protein HC display immunologic and biochemical identity. However, anti-protein HC stained almost all of the tested cell lines and normal lymphocytes. Blocking experiments with the purified protein were not successful. Antibodies reacting with a minor impurity (50,000 d) in the alpha 1-microglobulin or protein HC preparations could be absorbed from anti-alpha 1-microglobulin with normal leukocytes and a lymphoid cell line.

Absorption↗

Preferential replication of murine xenotropic type-C virus in human lymphosarcoma-derived cell lines.

Murine xenotropic virus, designated 698/X, was recovered by implantation of human lymphosarcoma-derived cells U-698M into nude mice of Giovanella's colony. The budded and extracellular particles revealed typical type-C morphology, the latter possessing reverse transcriptase (RT) activity and exhibiting a buoyant density 1.17 g/ml in sucrose gradient. In competitive radioimmunoassay using iodinated p30 of Rauscher MuLV, the 698X viral concentrate and cell extracts of both implanted lymphosarcoma cells (U-698M-N-1 and U-715M-N-1) were as effective as Gross MuLV, thus indicating the murine origin of the virus. The propagation of the 698/X virus in five human, four mouse (permissive for N- and B-tropic MuLV), two rat and one bovine cell lines was followed by RT, XC syncytia assays and EM investigations. The replication of the 698/X virus seems to be restricted mainly to both human lymphosarcoma-derived cell lines U-698M and U-715M. The new recovery of the virus from the nude mouse by implantation of U-175M cells has asserted its high tropism to human lymphosarcoma cells and its murine origin. The comparative response of mouse, rabbit and rat cells exposed to both NZB and 698/X xenotropic murine viruses exhibited host range differences between these viruses. The rabbit SIRC and rat embryonic cells REC were fully permissive for the murine xenotropic NZB virus, while low viral production was detected by RT assay only in 698/X virus infected SIRC cells.

Animals↗

Helix pomatia A hemagglutinin: selectivity of binding to lymphocyte surface glycoproteins on T cells and certain B cells.

Human and mouse lymphocytes were surface-labeled by lactoperoxidase-catalyzed iodination, or by galactose oxidase oxidation followed by reduction with tritiated sodium borohydride. The labeled cells were lysed with Nonidet P-40. Proteins binding to Helix pomatia A hemagglutinin (HP) were isolated by affinity chromatography on HP-Sepharose and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. A major cell surface glycoprotein (apparent mol. wt. 150 000, using reducing conditions) on human lymphocytes was responsible for almost all binding of HP. This protein was present on normal and malignant thymus-derived lymphocytes, e.g. thymocytes, blood T cells and T leukemia cell lines. It was also found on chronic lymphocytic leukemia cells, one null cell leukemia line, one unidentified leukemia line, one lymphoblastoid cell line of B origin and on one stem cell lymphoma line. In contrast, this protein was not found on various B cells at different steps of differentiation, e.g. four B lymphoma lines or one myeloma line. It was also absent from a histiocytic leukemia line. However, two of the four B lymphoma lines and the myeloma line had another HP-binding surface glycoprotein (mol. wt. 200 000) instead of the 150 000 protein. Studies of mouse lymphocytes similarly showed that thymus-derived lymphocytes (normal and malignant) but not normal adult B cells expressed a major HP-binding surface glycoprotein of apparent mol. wt. 130 000 (reducing conditions).

Agglutinins↗

A comparative study of the buoyant density distribution of normal and malignant lymphocytes.

Density distribution patterns of normal and malignant lymphocytes were compared following centrifugation to equilibrium on linear density gradients. For normal lymphocytes differences in the distribution patterns were observed between: (1) B and T cells, (2) central and peripheral cells, and (3) resting and activated cells. The findings suggested that cell density is determined by cell lineage the degree of differentiation and the stage of functional activation. Marked differences in the density distribution profiles were also observed among certain types of morphologically distinguishable lymphoproliferations. To some extent density analyses enabled the discrimination between CLL, follicular lymphomas and lymphoblastic lymphomas as well as between O-ALL and T-ALL. Density profiles of malignant lymphocytes failed to disclose any features specific for malignancies. But they revealed some similarities with distinct subsets of normal lymphocytes, i.e. between: (1) CLL and bone marrow lymphoid cells, (2) follicular lymphomas and follicular centre cells, and (3) lymphoblastic lymphomas and activated lymphocytes. These findings are further evidence supporting the hypothesis that the malignant transformation of phenotypically different lymphoproliferations takes place at different levels of lymphocyte differentiation.

B-Lymphocytes↗

Characteristic surface morphology of human and murine myeloma cells: a scanning and transmission electron microscopic study.

Cells from cultured human and murine myeloma cell lines and circulating leukaemic plasma cells from four patients with generalized myeloma were studied by transmission and scanning electron microscopy and time-lapse cinematography. Both circulating and cultured cells exhibited consistent surface architectures and varying numbers of prominent blebs of different sizes were seen, in addition to microvilli. The presence of surface blebs appears to be a characteristic feature for secreting and non-secreting myeloma cells.

Animals↗

Effects of prednisolone in 6 cases of glucocorticoid receptor-positive CLL.

The effect of treatment with prednisolone on clinical and laboratory variables was studied in 6 patients with chronic lymphocytic leukaemia (CLL). The laboratory variables analyzed on the leukaemic cells were surface immunoglobulin (S-Ig), sheep red blood cell receptors (SRBC), proliferative activity (PI) and glucocorticoid receptor (GR). In all cases the CLL was of B-cell type and the leukaemic cells contained a significant amount of GR. 4 out of 6 patients had a progressive disease with increased PI. On treatment they went into clinical remission, which was paralleled by a reduction in the leukaemic B-cell number and in PI. The amount of GR was unaffected. In 2 patients with nonprogressive disease, prednisolone produced no clearcut effect on clinical or laboratory variables.

Complement System Proteins↗

Presence of alpha-naphthyl acetate esterase activity in human haematopoietic cell lines and in fresh biopsy specimens of lymphoma and myeloma.

We have previously shown that non-proliferating human T- but not B-lymphocytes contain demonstrable amounts of acid alpha-naphthyl acetate esterase (ANAE). The usefulness of this histochemical marker for the diagnosis and classification of malignant lymphoid tumors was investigated by use of a panel of established normal and malignant human haematopoietic cell lines and fresh biopsy cells from malignant lymphomas and myelomas. The results showed that not only the T-cell derived acute leukaemia lines, but also histiocytic lymphoma and myeloma lines and some of the lymphoma (Burkitt and lymphocytic) and non-neoplastic lymphoblastoid cell lines with B-cell surface markers expressed strong ANAE reactivity. Some but not all of the immunoglobulin producing myeloma and lymphocytic lymphoma biopsies were ANAE-positive. Inhibition experiments with sodium fluoride and E-600 demonstrated that although the T-lymphocyte specific esterase is predominantly of 'A'-type, the malignant lines contain also non-specific 'B' esterase and pseudocholinesterase. As the presence of the various esterases did not demonstrate any specific distribution pattern among he haematopoietic cell lines of different origin, we concluded that the ANAE marker is no longer T-specific when malignant lymphoid cells are considered, and that the usefulness of this marker in routine diagnostic work therefore is limited.

B-Lymphocytes↗

The role of canine superficial ventricular muscle fibers in endocardial impulse distribution.

Thin sections of canine right and left ventricular endocardium and myocardium were studied in a tissue bath to compare conduction properties of intraventricular specialized conducting tissue [Purkinje fibers (PF)], the superficial layers of subendocardial ventricular muscle (SVM), and the deeper ventricular muscle (DVM) below this level. The study was carried out because of observations that some areas of the endocardium, which are devoid of either specialized conducting tissue or of PF-VM junctions between specialized conducting tissue and ventricular muscle, conduct relatively rapidly, favoring specific orientations of propagation. Preparations containing PF, SVM, and DVM were studied electrophysiologically and histologically. A technique of stripping limited areas of endocardium was used to expose DVM in order to determine its intrinsic calculated conduction velocity. In 12 preparations, the average calculated conduction velocity in PF was 1.62 m/sec, and the average in DVM was 0.26 m/sec. The SVM conduction velocity was intermediate between the two, averaging 0.98 m/sec when propagation was parallel to SVM fiber orientation. Conduction velocity transverse to SVM fiber orientation was not significantly different from DVM conduction velocity. Histologically, the most superficial layers of VM were oriented uniformly in the direction of rapid subendocardial conduction, in contrast to DVM fibers in which orientation varied. It is concluded that the geometric arrangement of SVM fibers may provide a means for rapid subendocardial conduction and impulse distribution at a conduction velocity intermediate between PF and DVM in areas devoid of specialized conducting tissue.

Animals↗

Prolonged serum insulin decreasing effects of two synthetic somatostatin analogues studied in vivo by a new animal method. Preliminary communication.

A newly developed in vivo method, using the ob-ob strain of obese-hyperglycaemic mice with permanently very high serum insulin values, makes it possible to detect more prolonged serum insulin lowering properties than in normal animals. Two newly synthesized analogues of somatostatin, D-alanine-somatostatin and des-alanine-des glycine-des-amino-somatostatin produced a more prolonged and greater decrease in the serum insulin values of ob-ob mice than did somatostatin. Our new in vivo method makes it possible to investigate the duration of insulin suppression of new derivatives.

Amino Acid Sequence↗

Human malignant lymphomas in vitro. Characterization of biopsy cells and establishment of permanent cell lines.

A series of 55 biopsies from different types of malignant lymphomas were characterized in short-term culture experiments and during prolonged growth in vitro. The majority of the lymphocytic lymphomas and half of the histiocytic lymphomas expressed surface immunoglobulin, either in monoclonal or polyclonal form, indicating B-lymphocyte derivation. No lysozyme production was noted in either type of lymphoma, giving further support to the notion that histiocytic lymphomas are not truly histiocytic. Production of beta2-microglobulin was higher in histiocytic than in lymphocytic lymphoma and Hodgkin's disease but did not significantly differ from the production observed in non-neoplastic lymph node disorders. Incorporation of 3H-thymidine varied greatly within each category of lymphoma; the highest mean labelling index was noted in histiocytic lymphoma, possibly reflecting the generally more malignant course in such cases. Epstein-Barr virus-associated nuclear antigen was observed in one case of Hodgkin's disease. Attempts to establish permanent tumor cell lines were successful only from two explants of lymphocytic lymphoma and one pleural effusion from histiocytic lymphoma. The two cell lines derived from lymphocytic lymphomas both exhibited B-lymphocyte characteristics. The histiocytic lymphoma line lacked lymphocyte markers, produced lysozyme and was found to be rich in cytoplasmic esterases. These features are consistent with a "true" histiocytic derivation of this line. Lymphoblastoid cell lines representing non-neoplastic EBV-carrying lymphocytes contaminating the biopsies were derived from 19 biopsies, with the highest frequency noted in cultures of biopsies from Hodgkin's disease. The tumor lines were all EBV-genome negative.

Antigens, Viral↗

Surface glycoprotein patterns of human haematopoietic cell lines.

Human EBV-positive and EBV-negative haematopoietic cell lines were shown to have different and easily distinguishable surface glycoprotein patterns as demonstrated using surface labelling by the galactose oxidase-tritiated sodium borohydride method.

B-Lymphocytes↗

Biochemical characteristics of chronic lymphocytic leukaemia. Glucocorticoid receptors, B and T lymphocyte surface markers, concanavalin A-induced agglutination and thymidine incorporation.

Chronic lymphocytic leukaemia (CLL) has a variable clinical course and there is a great need of new prognostic laboratory parameters in this disease. 24 CLL patients were subjected to routine haematological and clinical investigation. The leukaemic cells were analyzed for surface immunoglobulins, complement and sheep red blood cell receptors, Concanavalin A-induced agglutination, cytoplasmic glucocorticoid receptor and for proliferative activity by measurement of tritiated thymidine incorporation. The surface markers studied indicated that all cases were of B-cell origin. Only 5 of 23 patients studied had normal serum immunoglobulin levels. These cases showed a nonprogressive disease. 8 patients had increased infection tendency, all of whom had subnormal IgG levels; 4 of them also had subnormal IgA and IgM and 2 had subnormal IgA levels. 5 out of 6 patients with progressive disease and 3 of 11 with nonprogressive disease had an increased proliferative index, indicating a correlation between this parameter and disease progression. ConA agglutinability was not correlated to disease activity. Cells from 17 of 22 patients showed measurable amounts of glucocorticoid receptor. The 5 patients lacking this receptor had inactive disease.

Aged↗