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Biomedical subjects

C Neumann

Publications and source records attributed to C Neumann.

At least 181 records · Page 10Linked to original sources
PubMed1984

Migration inhibitory factors and macrophage differentiation.

It has been described before that only certain types of macrophages are capable to respond to lymphokines and that only certain macrophage phenotypes were able to migrate and to respond to migration inhibitory factors (MIF). With respect to the dissociation of MIF activities from a series of other biological activities, and with regard to the phenotype-associated response of macrophages to MIF it was asked: What are the characteristics of the MIF-responsive macrophage phenotype and what are the functional changes induced by MIF on macrophages in addition to inhibition of random migration? Bone marrow-derived macrophages on day 6 of culture were separated by hypotonic Percoll density gradient centrifugation into three distinct bands and analyzed for a variety of functions. It was found that migrating and MIF-responsive macrophages accumulate at a certain density. These macrophages were further characterized by monoclonal antibodies generated against murine macrophage phenotypes. One marker was found to be preferentially expressed by MIF-responsive macrophages. In order to study the inducibility of MIF responsiveness, bone marrow-derived macrophages on day 16 of culture which were poorly migrating and did not respond to MIF were induced to proliferate by the addition of L cell-conditioned medium. After proliferation had subsided, MIF sensitivity was restored. The effects of MIFs other than migration inhibition, on a number of functions which had been mapped within the cell cycle, were investigated. It was found that MIF acts anti-proliferative on "young", cycling macrophages. Non-cycling, mature macrophages were shifted to a state characterized by a decreased expression of transglutaminase and plasminogen activator and an increase of certain phenotypic surface markers. It is concluded that MIFs are differentiation-inducing signals, acting on the generation of macrophages from precursors but also in the recruitment of terminally differentiated macrophages to "inflammatory" type of macrophages which are functional in the induction of immune responses.

Animals↗
PubMed1984

Computed tomography, lymphography, and staging laparotomy: correlations in initial staging of Hodgkin disease.

One hundred twenty-one patients with newly diagnosed, previously untreated Hodgkin disease underwent abdominal and pelvic computed tomographic (CT) scanning and bipedal lymphography. These studies were followed by staging laparotomy, which included biopsy of the liver, retroperitoneal and mesenteric lymph nodes, and splenectomy. Correlation of the results of the imaging studies with the histopathologic diagnoses revealed a small--but significant--increased accuracy of lymphography compared with CT in assessing the retroperitoneal lymph nodes. The theoretical advantages of CT scanning in detecting lymphomatous deposits in lymph nodes about the celiac axis and the mesentery, or in the liver and spleen, were not confirmed. In part this was due to the relative incidence and the small size of individual lesions at these sites in patients with Hodgkin disease at the time of initial diagnosis and staging.

Adolescent↗
PubMed1983

Regulation of plasminogen activator secretion, interferon induction and proliferation in murine macrophages.

The purpose of this work was to study the interrelationship of proliferation and secretion of plasminogen activator (PA) and interferon (IFN) by murine macrophages. For induction of macrophage proliferation and secretion of PA, concanavalin A (Con A) was used. Secretion of IFN was induced by polyinosinic polycytidylic acid complex. The glucocorticoid dexamethasone acetate (DA) (10(-6)-10(9) M) inhibited Con A-stimulated secretion of PA and synthesis of DNA as evaluated by incorporation of [3H]thymidine. DA did not inhibit IFN induction. Preincubating macrophages with DA for 45 h reduced basal proliferation and secretion of PA but did not reduce responsiveness to Con A. Also retinoic acid, a modulator of carcinogenesis was used in inhibition studies because of its known antagonistic effects on lymphocyte mitogenesis. In macrophages a biphasic effect of retinoic acid (1 X 10(-5) - 5 X 10(-5)M) was found: (a) inhibition of DNA synthesis and secretion of PA during the first 45 h of incubation, and (b) enhancement of DNA synthesis (but not PA secretion) after 72 h. Secretion of IFN was not affected. It is suggested that secretion of PA but not IFN is linked to cell cycle traverse of macrophages.

Animals↗
PubMed1983

Vitamin cofactor saturation indices for riboflavin, thiamine, and pyridoxine in placental tissue of Kenyan women.

Vitamin cofactor saturations of placental enzymes were assayed in 54 Kenyan women. In addition, studies were conducted to determine whether placental vitamin deficiencies were associated with deficiencies in maternal or cord blood and to determine whether neonatal birthweights were influenced by vitamin nutriture. All samples were analyzed by vitamin cofactor saturation tests of glutathione reductase, transketolase, and glutamic-pyruvic transaminase. Standard indices were used to determine vitamin deficiencies. The activity of placental diamine oxidase, a pyridoxal phosphate-requiring enzyme was also measured and examined in relation to pyridoxine nutriture. No placental riboflavin deficiencies were found although 73% of maternal red blood cells (RBC) and 35% of cord RBC were deficient. Thiamine deficiencies were found in 15% of placentas, 59% of maternal RBC and 41% of cord RBC. Pyridoxine deficiencies occurred in 24% of placentas, 35% of maternal RBC, and 15% of cord RBC. Low birth weights were found to be associated with maternal riboflavin deficiencies. Maternal RBC riboflavin and thiamine deficiencies correlated with deficiencies in cord blood, and pyridoxine deficiencies in maternal RBC were associated with deficiencies in the placenta. A trend of lower placental diamine oxidase activity was noted in pyridoxine-deficient placentas and pyridoxine-deficient mothers.

Adolescent↗
PubMed1983

Evaluation of skin vasomotor reflexes by using laser Doppler velocimetry.

We used a laser Doppler velocimeter for measurement of skin blood flow in 63 healthy control subjects and in patients with dysautonomias. We measured vasoconstrictor responses to inspiratory gasp, standing, Valsalva maneuver, and cold stimulus. An abnormal profile was defined in terms of the percentage of abnormal test results, the results of individual tests, and the alterations in the shape of the recorded response. These measurements of vasomotor function may permit the diagnosis of focal abnormalities of peripheral nerve sympathetic failure.

Adolescent↗
PubMed1982

Modulation of suppressor mechanisms in allergic contact dermatitis: 5. Evidence that inhibition of suppressor T lymphocytes by Corynebacterium parvum is mediated by interferon.

Using a contact hypersensitivity model in BALB/c mice we have previously been able to show that Corynebacterium parvum or C. parvum serum (C.p.s.) of mice treated 24 hr before with C. parvum inhibited the suppressor T-lymphocyte (Ts-cell) response induced by epicutaneous antigen overload with 2,4-dinitrofluorobenzene (DNFB) or by i.v. injection of 2,4-dinitrobenzene sulfonic acid (DNBSO3) without inhibition of the T effector cell response (TDH-cell). In the present investigation we further analyzed the factor responsible for Ts-cell inhibition. Treatment of the C.p.s. with sheep-antimouse interferon (IFN) globulin neutralized its Ts-cell inhibitory effect. Intravenous (i.v.) injection of a crude mouse fibroblast IFN (340 U per mouse) 2 hr after i.v. application of a dose of DNBSO3 inducing tolerance had a similar Ts-cell inhibitory effect as observed with C.p.s. Injection of an electrophoretically pure alpha- and beta-IFN preparation (1000 U per mouse) increased contact sensitivity in mice sensitized with an antigen overload and inhibited the induction of Ts-cells by DNBSO3 i.v. This result is highly suggestive that the Ts-cell inhibitory factor in serum of C. parvum-treated mice is IFN and it shows that Ts-cells as compared to TDH-cells are susceptible to the inhibitory effect of highly purified IFN. This finding suggests that IFN may be an important immunoregulatory factor of delayed hypersensitivity not only in contact allergy but also in bacterial and viral defense.

Animals↗
PubMed1981

Transglutaminase as a marker for subsets of murine macrophages.

Transglutaminase was detected either at the single cell level by fluorescent staining with dansylcadaverine or in cell homogenates by incorporation of [14C] putrescine into alpha-casein. In the mouse it was found that erythrocytes, granulocytes, thymocytes or lymphocytes with or without concanavalin A stimulation were negative in the fluorescence test. Normal peritoneal washout macrophages and peritoneal exudate cells stained positive to varying degrees (induced with mineral oil 64%, with thioglycollate 50%, with proteose peptone 22%, normal washout 1%). Macrophages from bone marrow liquid cultures were 20% positive at day 3 and 100% at day 17. Promonocytes and monocytes were negative. Positively stained cells also phagocytosed opsonized sheep erythrocytes. The degree of staining varied considerably in the macrophage-like cell lines IC21 (100%), J774.2 (75%), P388-D1 (50%). This result and those from autoradiography studies indicate that expression of transglutaminase is not associated with the S-phase of the cell cycle. The fluorescence test correlates quantitatively with the [14C] putrescine incorporation test. The enzyme is Ca2+-dependent and appears neither to be on the outer cell surface nor being released into the culture medium. Circumstantial evidence indicates that it is also not compartmentalized in cytoplasmic vesicles. While the induction and modulation of enzyme expression is still under study, it is concluded that transglutaminase is a new marker for macrophages of a certain differentiation or activation state.

Animals↗
PubMed1981

Influence of various detachment procedures on the functional state of cultured murine macrophages.

Macrophages were obtained from seven-day-old bone marrow liquid cultures to which a colony-stimulating factor from L-cell-conditioned medium had been added. It was found that the yield of macrophages from the bone marrow liquid culture was dependent on the type and brand of culture dishes. Highest yields were obtained in teflon membrane bag cultures. The cumulative yield after serial passage of macrophages was 700-fold of the cell input after two months. After mechanical detachment from plastic culture dishes, the survival rate of cells was related to the brand of the plastic dish. Viability also varied greatly after pretreatment of cells with scandicain (28%), proteinase K (78%), or pronase (99%). After mechanical detachment of macrophages or pretreatment with scandicain, adherence to plastic, latex phagocytosis and chemotaxis was not or only slightly impaired, whereas the same functions after protease treatment were greatly reduced or even abolished and were only recovered after another culture period. Scandicain, proteinase K, and pronase treatment was mitogenic to macrophages in contrast to mechanical detachment. Pronase treatment also induced release of plasminogen activator activity. The results demonstrate that macrophages respond extremely sensitive to environmental conditions and to various insults by changing their functional state.

Animals↗
PubMed1980

Sequential expression of functions during macrophage differentiation in murine bone marrow liquid cultures.

In the presence of a colony-stimulating factor, murine bone marrow cells proliferate and differentiate into macrophages. This culture system was taken as a model to study the expression of various functions by macrophages in the course of maturation. Several tests were performed daily and in parallel from the same batch of cells. It was found that certain functions were expressed early and were also characteristic for mature macrophages such as Fc receptors, phagocytosis of latex beads and unspecific esterase activity. Other functions appeared and disappeared in an ordered sequence, such as the response to macrophage migration inhibitory factor and chemotactic factor as well as the production of interferon and of plasminogen activator. The time course of functional expression was strongly dependent on proliferation of precursor cells as well as proliferation of differentiated macrophages. It is suggested that the phenotypic expression of functions during differentiation is the basis for the functional heterogeneity of macrophages.

Animals↗
PubMed1980

Interferon production by Corynebacterium parvum and BCG-activated murine spleen macrophages.

Macrophages were identified to be a major source of interferon produced in murine spleen cell cultures after intravenous injection of Corynebacterium parvum (C. parvum), strain CN 6134 or Bacille Calmette Guérin (BCG). Another strain of C. parvum, CN 5888, which lacks RES stimulating activity and adjuvant activity in vivo, was not effective when injected intravenously. Protein synthesis was required for interferon activity to be produced and protein synthesis was also required for the antiviral state to be expressed. The antiviral activity was relatively stable to pH 2 and neutralized by an antiserum against virus-induced fibroblast interferon, thus exhibiting some properties of type I interferon. In vitro only CN 6134, the biologically active strain, could induce small amounts of interferon in spleen macrophage cultures. Macrophages from CN 6134 or BCG-infected athymic nu/nu mice produced similar interferon titers as their controls. It is concluded that infection with certain immunomodulators can activate splenic macrophages via a predominantly T-cell independent mechanism. Interferon in turn may operate locally as a mediator of immunoregulation.

Animals↗