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Biomedical subjects

T H Weber

Publications and source records attributed to T H Weber.

At least 37 records · Page 2Linked to original sources
PubMed1980

Non-specific cyclic nucleotide binding in leukemic leukocytes.

Extracts of leukemic lymphocytes and leukemic myelomonocytic cells bind significantly more cAMP/mg protein than do normal cells. The binding of cAMP in leukemic cells is non-specific since the binders are unable to effectively discriminate between cAMP and cGMP in contrast to normal cells. When normal lymphocytes are activated in vitro with mitogens, their cAMP-binding capacity is increased, but the binding retains the specificity of normal cells. Thus in malignantly transformed leukocytes, cAMP-binding is characterized by a high degree of non-specificity, compared with the binding in resting or proliferating normal leukocytes.

Cyclic AMP↗
PubMed1980

Characterization of human lymphocyte surface receptors for mitogenic and non-mitogenic substances.

To compare the receptor patterns for mitogenic and non-mitogenic substances, surface glycoproteins of human lymphocytes were labelled with the lactoperioxidase-catalysed iodination technique and with a galactose oxidase-tritiated sodium borohydride technique. Labelled cells were detergent-solubilized, and the lysates were allowed to react with insolubilized purified mitogenic lectins, phytohaemagglutinin, leucoagglutinin and an insolubilized non-mitogenic lectin, oxidized leucoagglutinin. Lectin-reactive proteins were eluted with sodium dodecyl sulphate (SDS) buffer. Cell membrane components reactive with anti-lymphocyte globulin (ALG) were retrieved by indirect immunoprecipitation with protein-A-bearing staphylococcus Cowan I strain (SaCI). Lectin- and ALG-reactive proteins were analysed by SDS polyacrylamide gel electrophoresis. Iodinated glycoproteins regularly showed four major components with molecular weights of 120,000, 70,000, 60,000 and 43,000 daltons, respectively, on 7% gels. An additional broad peak in the molecular weight range 20,000--35,000 daltons was found on 10% gels. Tritiated glycoproteins also showed four major components with MW 120,000, 70,000, 60,000 AND 42,000, RESPECTIVely, which reacted with lectin and ALG. In addition, ALG reacted with some glycoproteins with MW between 150,000 and 230,000 daltons. On 10% gels additional lectin- and ALG-binding glycoproteins with MW around 30,000 daltons were found. The similarity in structures bound by mitogenic and non-mitogenic substances indicates that lymphocyte activation may depend on some property conferred by the mitogen.

Antilymphocyte Serum↗
PubMed1980

Leucocyte migration inhibition factor (LIF) and antithrombin III (AT III).

The activity of LIF, produced in vitro by sensitized lymphocytes exposed to the appropriate antigens, is readily abolished in the simultaneous presence of heparin and thrombin. Heparin or thrombin alone are without significant effects. Adding AT III together with heparin and thrombin restores the LIF activity. We suggest that the migrating leucocytes on their cell membranes have receptors, composed of AT III-like molecules, which are blocked or destroyed, by forming complexes with heparin and thrombin. However, the heparin-thrombin complex will preferentially interact with AT III added to the culture medium, thus leaving the cellular receptors free to interact with LIF.

Antithrombin III↗
PubMed1979

A case of pure monocytic leukaemia in a child - characterization of cellular morphology, membrane markers, surface glycoproteins and karyotype.

A case of pure monocytic, 'Schilling-Type' leukaemia in a 9-year-old boy is described. The leukaemic cells resembled monocytes and were abundantly present in blood and bone marrow. They were strongly alpha-naphthyl-acetate-esterase positive, contained fine PAS-positive granules and did not stain by Sudan B. They were negative for surface bound and intracytoplasmic IgG, but had a high density of membrane Fc-receptors and showed phagocytosis. The surface glycoprotein pattern resembled that of monocytes, but was clearly different from those of lymphocytic and myelocytic cells or those of acute lymphocytic leukaemia cells. The karyotype of bone marrow cells was 44,X, -15, -21, +mar,del(2)(p11), with the missing Y-chromosome located in the marker chromosome. Especially the surface glycoprotein and membrane receptor analyses aided in the accurate classification of the monocytic origin of the leukaemic cells.

Antigens, Surface↗
PubMed1978

Transient erythroblastopenia in childhood. A study of 15 cases.

A survey is presented of 15 patients from the Aurora Hospital and 35 patients reported in the literature with transient erythroblastopenia of childhood (TEC). The children were hospitalized because of pallor and tiredness, some of them having signs of mild infection. They displayed normochromic anaemia, reticulocytopenia and erythroblastopenia during the severe stage of the disease. In addition, they had moderately high values for serum iron and iron-binding saturation. No other haematological, chemical or cytogenetic abnormalities could be demonstrated. 80% of the children were between 6 and 48 months old and the sexes were equally affected. In the 15 patients from the Aurora Hospital a barely significant (p=0.02-0.05) association with blood group A was recorded. Remission, indicated by a rise in the reticulocyte count, begins within a week after the diagnosis is made, even without treatment. The aetiology of the disease is unknown. Analysis of the red blood cell population at the time of diagnosis indicates that damage to the red cell precursors has occurred 2-3 months before the child is brought for examination.

Anemia, Aplastic↗
PubMed1977

Effect of buffer composition on binding of adenosine 3':5'-cyclic monophosphate by bovine adrenal extracts.

The binding of cyclic [3H] AMP by bovine adrenal extracts was studied in different buffer systems; 50 mM-Tris/HCl, pH 7.5, buffer containing 4mM-EDTA (disodium salt) offered advantages such as low non-specific interference and high binding affinity. 2-Mercaptoethanol decreased, but EDTA and theophylline increased, the specificity of cyclic [3H]AMP binding as expressed by the displacement of cyclic [3H]AMP by a 1000-fold excess of unlabelled cyclic GMP. The study indicated heterogeneity of the binding material. Mg2+-dependent binding may be eliminated in Tris/EDTA buffer. The heterogeneity and the specificity of intracellular cyclic AMP binders and their dependence in environmental factors should be considered in the evaluation of cyclic AMP binding and second-messenger systems.

Adrenal Glands↗
PubMed1977

Long-term of phenytoin: Effects on whole blood and red cell folate and haematological parameters.

Patients treated when phenytoin for periods of several months or years have slightly, but significantly lower whole blood and red cell folate values than comparable controls. This holds true irrespective of whether folate is determined microbiologically with Lactobacillus casei or by a radioligand method using the bovine milk binder. Haematological parameters including Hb, MCH, MCV and red blood cell counts did not show any alterations and no patient developed any signs of anaemia. This indicates that long-term use of phenytoin does not cause a clinically significant state of folate deficiency, unless some other contributing factors are present.

Adolescent↗
PubMed1977

Migration inhibition factor and the blood clotting system: effects of defibrination, heparin and thrombin.

Heparin is not suitable as an anticoagulant in the leucocyte migration test used to demonostrate the presence of migration inhibition factor (MIF) due to a rapid disappearance of the response after even a short storage of the blood. The use of defibrinated blood is highly recommended and defibrinated blood can be stored for at least 90 min without any diminution of the response. The change in response when using heparinized blood is not due to any direct effect of heparin, because heparin has no effect when added to defibrinated blood. However, heparin, added together with thrombin, is capable of abolishing the MIF effect completely. The basis for this phenomenon is most probably the binding of the heparin-antithrombin cofactor (AT III) to a complex with heparin and thrombin. The activity of MIF requires the presence of AT III, its esterase-inhibiting activity probably being crucial, in order to express MIF activity on macrophages. This mechanism forms a link between certain cellular immune reactions and the blood-clotting system.

Blood Coagulation↗
PubMed1976

Renin-aldosterone axis in ethanol intoxication and hangover.

The renin-aldosterone system was studied in human volunteers during ethanol intoxication and hangover. Plasma renin activity increased more than 100%, when 1.5 - 2.3 g ethanol per kg body weight was ingested over a three hour period. During hangover the increase even exceeded 200%. Plasma aldosterone concentration decreased during ethanol intoxication, but increased greatly during hangover. It is suggested that the stimulation of the renin-aldosterone axis during ethanol intoxication and hangover is due to dehydration and increased activity of the sympathetic nervous system.

Adult↗
PubMed1976

Radiation sensitivity of lymphocytes from human blood and from the thoracic duct.

Peripheral blood and thoracic duct lymphocytes are sensitive to irradiation. However, a distinct population of resistant lymphocytes exists, which is characterized by reactivity to a very low dose of lymphocyte-stimulating lectins in vitro. Blood lymphocytes are rapidly eliminated from the circulation after radiation damage. An analysis of the function of blood lymphocytes is thus of little or no use in assessing the therapeutic effect of extracorporeal irradiation. Lymphocyte activation must accordingly also be unsuitable for use as a biologic dosimeter after accidental total body irradiation.

Blood↗