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Biomedical subjects

N R Ling

Publications and source records attributed to N R Ling.

At least 73 records · Page 4Linked to original sources
PubMed1980

Quantitation of human total IgG, kappa IgG and lambda IgG in serum using monoclonal antibodies.

Monoclonal antibodies to human IgG have been applied, in parallel with polyclonal antisera, to the routine quantitation of human IgG. Two monoclonal antibodies directed against spatially distinct epitopes have been used in combination to form insoluble complexes exhibiting turbidity. Quantitation was performed using a centrifugal fast analyser and a correlation coefficient of 0.979 was obtained for the two estimations. The technique has been further developed to allow the separate quantitation of kappa IgG and lambda IgG in whole serum.

Antibodies↗
PubMed1980

B lymphocytes in contact dermatitis.

The expression of immunoglobulin on the membrane of peripheral blood lymphocytes of patients with contact dermatitis has been investigated using a sensitive rosette technique. The proportion of such cells in these patients is increased compared to normal values. However, the absolute values obtained are very much lower than has been reported from previous studies. The re-evaluation of immunoglobulin expression is discussed against a background of improved methodology and the established finding that individual lymphocytes may express more than one isotype.

Adolescent↗
PubMed1980

Suppression of mixed lymphocyte reactions by pregnancy serum.

Maternal lymphocyte function, as assessed by stimulation with cells from a human lymphoid line, is normal in pregnancy. Maternal serum, however, contains immunosuppressive factor(s), demonstrable by 29 weeks of pregnancy, and having a greater effect at 36 weeks on mixed lymphocyte reactions. These immunosuppressive factor(s) block all mixed lymphocyte reactions to the same extent and are not specific towards those stimulated by paternal antigens. Anti-B cell (dr) alloantibodies, presumably directed against foetal antigens, are not uncommon in maternal serum even in early pregnancy. There is some suggestion that the presence of these antibodies in early pregnancy is associated with selective inhibition of maternal lymphocyte stimulation by paternal antigen. No correlation was found between the presence or absence of serum suppressive factors and the clinical course of the pregnancy.

B-Lymphocytes↗
PubMed1979

Ingestion of dyed-opsonised yeasts as a simple way of detecting phagocytes in lymphocyte preparations. Cytophilic binding of immunoglobulins by ingesting cells.

Procion-dyed yeasts which have been incubated in fresh serum and washed are readily ingested by human blood monocytes and tumour macrophages during a 30 min incubation period. Uptake is enhanced by centrifugation. Intracellular yeasts can be readily distinquished from extracellular by their much slower uptake of toluidine blue. Yeast ingestion is a much more reliable test for blood monocytes than the latex bead test and it is easier to read. The ingestion test may be combined with a rosette test for surface immunoglobulins (SmIg). Since the yeasts take up immunoglobulins from human serum during the complement-coating stage it is necessary, in a combined ingestion-SmIg test, to use fresh serum from another species (sheep) for opsonisation of the yeasts. A technique is described for reducing the number of immunoglobulin-bearing monocytes to a low level with a combined ingestion-SmIg rosette technique to detect residual immunoglobulin-bearing phagocytes.

Animals↗
PubMed1979

Growth enhancing property of human monocytes from normal donors and cancer patients.

Peripheral blood monocytes, but not other leucocytes, from healthy donors, were shown to enhance the DNA synthesis of three cell lines. The effect was very marked on an epithelial (Chang) and lymphoid (CLA-4) cell line derived from normal tissues, and less marked on a carcinoma-derived line (HT-29). The enhancement was demonstrable over a wide range of monocyte:cell line ratios, and some activity was present in supernates from monocytes cultured alone or with a cell line. Furthermore, monocytes from gastric carcinoma patients did not enhance Chang and CLA-4 cells to the same extent, relative to the healthy donors.

Adenocarcinoma↗
PubMed1978

Expression of immunoglobin G on blood lymphocytes in chronic lymphocytic leukaemia.

A sensitive rosette test utilizing antibody-coated red cells has been applied to the study of the immunoglobulins on the surface of blood lymphocytes in chronic lymphocytic leukaemia (CLL). Contrary to other reports, IgG has been found to be a common surface membrane immunoglobulin (SmIg) on CLL cells. The reasons for this variation are discussed. Evidence is presented to show that (a) the anti-IgG-coated erythrocytes really are detecting IgG and not a cross-reacting substance, (b) the IgG is intrinsic to the cell and not cytophilically bound and (c) Fc-binding and other artefacts have been excluded. Expression of Ig by individual cells was studied by using mixtures of fluorescein- and rhodamine-labelled red cells coated with various anti-Ig. Fifty-one cases of untreated CLL were tested and the lymphocytes of thirty-eight of these cases bore Ig of a single light chain type. These cases could be classified on the basis of their lymphocyte SmIg as follows: eighteen expressing M and D and G, eleven expressing D and G but not M, six expressing M and D but not G, and three expressing G alone.

Humans↗
PubMed1977

Use of antibody-coated red cells for the sensitive detection of antigen and in rosette tests for cells bearing surface immunoglobulins.

Conditions for an improved chromic chloride method for the attachment of antibody to red cells are described. The method, which is applicable to whole Ig fractions as well as affinity-purified antibodies, is reproducible and has a sensitivity for detection of antigen in the nanogram range. The coated cells may be used in a rosette assay for the detection of cell surface-bound antigens.

Antibodies↗
PubMed1977

Combined T and B lymphocyte marker test in lymphoproliferative disorders.

The combined T and B lymphocyte marker test of Mendes et al (1974) has been developed to provide an easy, reproducible test for clinical practice. It has been used to study subpopulations of peripheral lymphocytes in patients with lymphoid malignancies. Significant increases in the numbers of lymphocytes which bind both sheep erythrocytes (E) and the fixed, third component of complement (C3) have been found using this test, in the peripheral blood of all untreated lymphosarcoma (L/SA) patients and T cell acute lymphoblastic leukaemia (ALL) patients. Such increases were not found in blood from patients with chronic lymphatic leukaemia (CLL), other non-lymphoid malignancies, null-cell ALL or normal individuals. These mixed E and C3 receptor bearing cells may be Fc receptor positive and represent a separate subpopulation of lymphocytes.

B-Lymphocytes↗
PubMed1977

Lymphocyte stimulation by herpes simplex virus (HSV) antigens. 1. Culture conditions, cell fractionation and presentation of HSV antigens.

Optimal culture conditions for rabbit lymphocytes were established. Inclusion of 2-mercaptoethanol in the medium greatly enhanced responses. Lymphocytes from the blood of HSV-immunized rabbits responded specifically in vitro to heat-killed (56 degree, 60 min) or UV-inactivated HSV preparations. A UV dose of 13,392 ergs/mm2 was the most suitable inactivating dose. Oral intramucosal injection was the most effective way of generating blood lymphocyte responses to HSV, but animals immunized in tradermally or in tramuscularly with HSV in Freund's adjuvant also produced antigen-reactive cells after five or more immunizations. There were differences in the shape of the dose-response curves to various HSV1 mutants which were probably due to differences in the production of "stimulatory" and inhibitory antigens. Appreciable lymphocyte stimulation could be obtained with tissue culture fluid and enveloped virus antigens. Lymphocytes from HSV1-immune animals were also responsive to HSV2 antigens.

Animals↗
PubMed1977

DNA-synthesizing cells in the blood in coeliac disease and inflammatory bowel disease.

The level of 3H-labelled thymidine ([3H]TdR) incorporation of blood cells of patients with coeliac disease was shown in two separate studies to be significantly lower than that of a normal control group. In the first study the 'background' DNA synthesis in unstimulated cultures containing a standard number of blood lymphocytes was measured on days 4, 5 and 6. In the second study a standard volume of freshly drawn whole blood was added to culture medium and the [3H]TdR incorporation measured over the first 24 hr and from 48 to 72 hr. In all cases the [3H]TdR incorporation of cells of coeliac patients on a normal or a gluten-free diet was lower than that of the control group. It is suggested that sequestration of DNA-synthesizing cells in the mucosa of the small bowel may partly explain these results. In whole-blood cultures from patients with inflammatory bowel disease in remission [3H]TdR incorporation over the first 24 hr was raised in Crohn's disease but normal in ulcerative colitis.

Blood Cell Count↗
PubMed1975

Lymphocyte stimulation with skin cells. A function of maturation.

Cell monolayers grown from trypsin dispersions of whole rat embryos were tested for their capacity to stimulate allogeneic rat thymus cells in mixed cell cultures. Cells from whole embryos of only 15-days gestation were virtually ineffective at stimulating allogeneic thymus cells. Cells from 19-day-old whole embryos produced definite stimulation and stronger stimulation was obtained with skin cell monolayers prepared from these embryos. The average amount of allogeneic stimulation obtained with rat skin cells increased with the age of the donor animals. The greatest degree of stimulation occurred when the skin cells were obtained from rats about 1 week postpartum. Thereafter, the stimulating potential of allogeneic skin cells declined and was found to stabilize at the levels observed when adult skin cells were used as the stimulator cells. Neither rat brain cells nor rat kidney cells (taken from embryos, neonates, and adults) were capable of inducing allogeneic rat thymocytes to undergo significant transformation in culture. We conclude that the in vitro lymphocyte response to skin cell stimulation is a function of skin cell maturation, and that the inability of kidney cells or brain cells to provoke the same sort of stimulation is not attributable to antigen loss during or after foetal development, but exists as a feature of these cells at the earliest stages of differentiation.

Animals↗