Search PubMed⌕ Search

Biomedical subjects

T J Yang

Publications and source records attributed to T J Yang.

At least 91 records · Page 5Linked to original sources
PubMed1982

Effect of antiserum on leukemia L5178Y cells: [3H]thymidine incorporation does not reflect DNA synthesis.

1. The total amount of DNA present in L5178Y cells treated with antiserum in the absence of complement was decreased whereas the rate of incorporation of [3H]thymidine into DNA during a 1 hr pulse was increased as compared with those of controls. 2. This increase in specific activity of [3H]thymidine in the DNA of antiserum-treated cells appeared to be due, at least in part, to an increase in thymidine kinase activity.

Animals↗
PubMed1982

Increase in the serum macrophage migration inhibitory activity and lysozyme in dogs affected with cyclic hematopoiesis.

Cyclic neutropenia (CN) is an inherited disease known to occur in both humans and Gray Collie dogs. In dogs, the disease is characterized by a profound and cyclic decrease in circulating granulocytes at 12-day intervals. Other formed elements of the blood also show cyclic changes and thus the disease is also called cyclic hematopoiesis (CH). In this study, daily serum levels of lysozyme and a factor with macrophage migration inhibitory (MIF) activity were assayed. Both MIF activity and lysozyme levels were elevated more than 2-fold and fluctuated cyclically in CH dogs during the 12-day cycle: CH dogs CH 490 and CH 491, had 32.7 +/- 16.8% and 35.9 +/- 18.3% migration inhibitory activity, respectively, as compared to 15.1 +/- 1.4% in normal dog N 492; CH 490 and CH 491 had 78.7 +/- 43.7 units and 86.9 +/- 58.7 units of lysozyme, respectively, as compared to 33.4 +/- 1.7 units in N 492. The change of MIF activity tended to precede that of lysozyme activity in CH dogs. Furthermore, MIF levels and monocyte counts correlated significantly during the 12-day neutropenia cycle (CH 490, r = 0.677, P less than 0.001; CH 491, r = 0.583, P less than 0.01).

Agranulocytosis↗
PubMed1981

Sequential changes in peripheral blood leukocyte adherence inhibition (LAI) reactivity during progressive growth and spontaneous regression of canine transmissible venereal sarcoma.

Sequential changes in canine transmissible venereal sarcoma (CTVS) extract-induced leukocyte adherence inhibition (LAI) reactivity of peripheral blood leukocytes (PBL) were monitored in dogs from the time of tumor inoculation through progressive growth and spontaneous regression or surgical excision of CTVS. The time-course profiles of LAI reactivity of tumor dog PBL correlated with the clinical stage of tumor growth, substantiating our previous findings in a cross-sectional study. The kinetics of the time-course appearance of LAI reactivity observed and the demonstration of a rapid anamnestic response following tumor challenge indicate further that LAI is a reliable in vitro measure of in vivo tumor immunity. A significant increase in CTVS antigen extract-induced LAI reactivity observed in the PBL during tumor regression suggest that LAI reflects a function effector cell mechanism associated with spontaneous regression of CTVS. By contrast, absence of significant LAI reactivity of PBL during progressive tumor growth suggests the presence of serum blocking factors. In addition a substantial rebound in LAI reactivity observed in the PBL of dogs 3 to 7 days following surgical excision of progressively growing CTVS provides further evidence that tumor-cell components are associated with progressive tumor growth and diminished LAI reactivity.

Animals↗
PubMed1981

Canine transmissible venereal sarcoma: leukocyte adherence inhibition (LAI) reactivity of various lymphoid tissues of dogs with tumors at different stages of growth.

Leukocyte adherence inhibition (LAI) reactivity of various lymphoid tissues of dogs with canine transmissible venereal sarcoma (CTVS) at different stages of growth was determined by the tube LAI test. Tumors were classified at the time of excision into progressor, steady state, and regressor stages of growth. The LAI reactivity to CTVS antigen extract of spleen, draining and non-draining lymph-node cells, and peripheral blood leukocytes of regressors (non-adherence index--NAI of 172.8 +/- 46.8, 148.1 +/- 64.7, 138.7 +/- 47.3, and 172.2 +/- 60.7, respectively) was significantly greater than that of progressors (46.1 +/- 20.0, 38.5 +/- 21.5, 50.2 +/- 30.0, 24,6 +/- 37.2, respectively, p less than 0.001) and normal dogs (47.5 +/- 22.8, 54.6 +/- 24.6, 26.7 +/- 14.0, 50.9 +/- 22.4, respectively, p less than 0.001). In contrast, LAI reactivity of progressor lymphoid tissues to CTVS antigen extract did not differ significantly from that of normal dogs. LAI reactivity of lymphoid tissues from steady state tumor bearers (97.9 +/- 39.2, 80.7 +/- 47.3, 87.1 +/- 40.0, 85.1 +/- 53,9, respectively) was intermediate between and significantly different from LAI reactivities of regressor (p less than 0.05) and progressor (p less than 0.01) lymphoid tissues. Significant LAI reactivity observed in regressors suggests the presence of a functional effector cell mechanism associated with spontaneous regression of CTVS. The three distinct patterns of LAI reactivity observed in tumor-bearing dogs appear to correlate with the clinical course of tumor growth.

Animals↗
PubMed1981

Canine transmissible venereal sarcoma: distribution of T and B lymphocytes in blood, draining lymph nodes and tumours at different stages of growth.

The levels of T, B and null lymphocytes in the peripheral blood, draining lymph nodes, and tumour masses at different growth stages in dogs transplanted with canine transmissible venereal sarcoma (CTVS) were determined by immunofluorescence techniques. The tumours were classified at excision into "progressor", "steady state", and "regressor" stages of growth. The percentage of B cells in the lymphocytes infiltrating into the progressively growing tumours (n = 10, 37.3 +/- 7.4%) was significantly higher (P less than 0.025) than that in regressing tumours (n = 21, 26.1 +/- 1.9%). In contrast, the percentage of T cells in the lymphocytes infiltrating into the regressing tumours (n = 21, 61.2 +/- 2.6%) was significantly higher (P less than 0.005) than that in the progressively growing tumours (n = 10, 34.0 +/- 5.1%). The tumours at the steady-state growth stage (n = 9) had 50.8 +/- 5.7% infiltrating T-cells, which was significantly higher (P less than 0.005) than the progressors and lower (P less than 0.005) than the regressors. The percentage of null cells of progressors (n = 10, 26.0 +/- 6.9%) was significantly (P less than 0.025) higher than in regressors (n = 21, 13.5 +/- 2.9%). The draining lymph nodes of progressor dogs (n = 5) had significantly fewer (P less than 0.025) B cells (8.2 +/- 2.3%) than in normal (n = 5, 16.1 +/- 3.1%), regressors (n = 12, 19.1 +/- 1.7%) and steady-state dogs (n = 5, 15.8 +/- 2.6%). Although there was slight lymphopenia and fluctuation of null cells, no significant differences in T- and B-lymphocyte levels were noted in the peripheral blood of the tumour dogs (n = 44) studied.

Animals↗
PubMed1981

Autorosette formation of erythrocytes on peripheral blood mononuclear cells in dogs vaccinated with canine distemper live-virus vaccine.

A time course study of the peripheral blood leukocytes of dogs vaccinated with canine distemper live virus (a paramyxovirus) vaccines showed that autorosette-forming leukocytes appeared from day 3 to day 10 after vaccination. The number of these cells peaked at day 7 when as many as 35% of mononuclear cells formed rosettes with autologous erythrocytes. In contrast, in nonvaccinated dogs, only 0.6 +/- 0.3% (standard error of the mean) of mononuclear cells formed rosettes throughout the 2-week period.

Animals↗
PubMed1981

Identification of canine lymphocyte populations by immunofluorescence surface marker analysis.

A T-cell-specific rabbit anti-dog thymocyte antiserum was prepared and used in an indirect fluorescent antibody technique to identify T lymphocytes. The antiserum was rendered specific by absorptions with normal dog red blood cells, lyophilized serum, and bone marrow cells. By the indirect immunofluorescence assay, 73.6 +/- 1.2 (SEM)% of the peripheral blood lymphocytes were identified as T lymphocytes. By direct immunofluorescence assay of surface membrane immunoglobulin-positive lymphocytes, 18.2 +/- 0.8% of the peripheral blood lymphocytes were identified as B lymphocytes. The two assays used in conjunction can thus identify over 90% of the peripheral blood lymphocytes as either T or B lymphocytes, with the remaining 8.2 +/- 1.0% as null cells.

Animals↗
PubMed1981

Identification and physicochemical characterization of a tumor-associated antigen from canine transmissible venereal sarcoma.

A tumor antigen associated wtih canine transmissible venereal sarcoma (CTVS) has been identified and partially characterized. The antigen was demonstrated in 3-M KCI and saline extracts of washed CTVS cells. Rabbit anti-CTVS antisera absorbed wih glutaraldehyde cross-linked normal dog serum and pooled homogenates of canine spleen, thymus, lymph node, and liver were used to identify the antigen. The specificity of the rabbit anti-CTVS antiserum for the CTVS antigen was established by use of immunodiffusion, two-dimensional electrophoresis, and the enzyme-linked immunosorbent assay (ELISA). Extracted CTVS antigen was fractionated by Sephadex G-200 chromatography, and the antigen factions were identified with the use of absorbed rabbit anti-CTVS antiserum and the ELISA technique. Antigen activity was detected in samples with estimated molecular weights greater than 70,000 daltons. Antigen fractions reacted with absorbed anit-CTVS antiserum to form a single precipitation band in immunodiffusion studies. Extraction of CTVS antigen with 3 M KCl and saline in the presence of a protease inhibitor did not significantly alter the antigen activity or molecular weight of the CVTS antigen. Cytoplasmic and nucleolar fluorescence were observed in an indirect immunofluorescence test with the use of acetone-fixed CTVS cells and absorbed anti-CTVS antiserum. The CTVs antigen activity was greatly reduced by trypsin digestion, by incubation for 1 hour at 65 degrees C, and by exposure to pH 2.8, 4.0, and 11.0 for 1 hour each.

Animals↗
PubMed1981

T and B lymphocyte levels in the peripheral blood of dogs affected with cyclic neutropenia.

Canine cyclic neutropenia (CN), a heritable disease of Collie dogs, is characterized by the periodic cycling of formed elements of blood and the near disappearance of neutrophils every 11-12 days. Studies suggest that lymphocyte activity and regulatory mechanisms may be abnormal in CN. In this study, an immunofluorescence in the peripheral blood of normal CN Collies. Normal Collie dogs (N = 10) had 73.0 +/- 2.4% T-lymphocytes, whereas CN dogs (N = 4) had only 63.2 +/- 1.9% similar cells among peripheral blood lymphocytes (P less than 0.005). Studies on B-lymphocytes showed that normal Collie dogs (N = 10) had 17.8 +/- 2.0%, whereas CN dogs (N = 4) had 29.6 +/- 3.3% B-lymphocytes (P less than 0.005). Absolute counts for B-lymphocyte levels for 2 CN Collie dogs (N = 10) had 17.8 +/- 2.0%, whereas CN dogs (N = 4) had 29.6 +/- 3.3% B-lymphocytes (P less than 0.005). Absolute counts for B-lymphocytes were also increased in CN dogs. In a related study, daily changes in T- and B-lymphocyte levels for 2 CN Collies and 1 age-and-sex matched normal Collie were monitored over the course of a 2-week hematopoietic cycle. Similar differences in peripheral blood T- and B-lymphocyte levels, as mentioned above, were found between the CN Collies and the normal Collie. The absolute B-lymphocyte counts for CN Collies also showed a statistically significant increase (P less than 0.005) over counts for the normal Collie, and daily changes in both B- and T-lymphocyte counts were always greater for CN Collies than for normal Collies.

Agranulocytosis↗
PubMed1981

Identification of bovine T- and B-lymphocyte subpopulations by immunofluorescence surface marker analysis.

A T-cell specific goat anti-bovine thymocyte antiserum was prepared for use in identifying T lymphocytes by an indirect fluorescent antibody (FA) technique. The antiserum was made specific for T lymphocytes through adsorptions with normal bovine RBC, normal serum, and bone marrow cells. It reacted with more than 95% of the thymocytes and less than 5% of the bone marrow cells. By the indirect FA assay, 72.9 +/- 5.7% (SD) of the peripheral blood lymphocytes of adult cows (n = 19) were identified as T lymphocytes. With the previously reported total B-lymphocyte number of 26.9 +/- 4.4%, as determined by a mixture of antiimmunoglobulin (Ig)G, anti-IgA, and anti-IgM, the 2 assays, in conjunction, can thus identify over 95% of the peripheral blood lymphocytes as either T or B lymphocytes. With the use of individual Ig class- and subclass-specific antisera in the direct FA assay, the peripheral blood lymphocytes of adult cows (n = 15) were shown to consist of 8.5 +/- 3.1% IgG1-bearing lymphocytes, 3.5 +/- 2.2% IgG2-bearing lymphocytes, 7.0 +/- 2.4% IgA-bearing lymphocytes, and 13.4 +/- 2.6% IgM-bearing lymphocytes--indicating that although the majority of B lymphocytes possess IgM on their surface, in cattle ther are many B lymphocytes without surface membrane (Sm)IgM, but with only SmIgG1, SmIgG2, or SmIgA.

Animals↗
PubMed1980

Inhibition of calcium and glucose uptake by murine leukemia L5178Y cells treated with antiserum.

Studies were performed to determine whether decreases in transport of calcium and glucose might be among the earliest changes triggered by the antigen-antibody reactions occurring on the cell surface of murine leukemia L5178Y cells after treatment with rabbit antisera. After treatment with antisera, in the absence of complement, these cells exhibited a decreased uptake of 45Ca, 2-deoxy[3H]glucose, and 3-0-methyl[3H]glucose. These changes occurred rapidly, within 2 minutes after the addition of antiserum, in contrast to the previously reported inhibitory effects of antiserum on DNA, RNA, and protein synthesis, which became demonstrable only after 4 to 8 hours. The kinetics of uptake of the radioactive substrates was biphasic, with a very rapid initial uptake followed by less rapid linear uptake. The precise mechanism of cell growth inhibition remains to be elucidated, but one of the initial effects of antiserum treatment may be a perturbation at the cell membrane such that transport of specific nutrients is decreased, resulting in the observed effects on macromolecular synthesis.

Animals↗
PubMed1980

Depression of B-lymphocyte levels in the peripheral blood of cows with mastitis.

The levels of B-lymphocytes in the peripheral blood of normal and mastitic cows were evaluated by fluorescent-antibody and erythrocyte-antibody-complement-rosetting techniques. Normal cows (N = 8) had 26.9 +/- 4.4% surface membrane immunoglobulin-positive lymphocytes, whereas mastitic cows (N = 6) had only 16.3 +/- 3.6% similar cells among lymphocyte preparations purified by the Ficoll-Paque density gradient separation and carbonyl iron phagocytosis methods. Studies on smiliar lymphocyte preparations by erythrocyte-antibody-complement-rosetting techniques showed that normal cows (N = 12) had 33.5 +/- 7.1% erythrocyte-antibody-complement-rosetting lymphocytes, whereas mastitic cows (N = 6) had 20.5 +/- 6.0% similar cells.

Animals↗
PubMed1980

Karyotype analysis of leukocytes of gray collie (cyclic neutropenia)-normal bone marrow transplant chimeras six years after transplantation.

Karyotype analysis was made on the leukocytes of 2 gray Collie (cyclic neutropenia)-normal bone marrow transplant chimeras transplanted 6 years previously to correct cyclic neutropenia of the gray Collie syndrome. In a male-to-female transplant chimera, all of the to metaphase spreads showed the karyotype of male donor origin. In this and the male-to-male chimera, the morphology of all chromosomes examined showed no gross anomalies or breaks which might be of recipient origin.

Agranulocytosis↗
PubMed1979

Adaptation of enzyme-linked immunosorbent assay to the avian system.

A microplate enzyme-linked immunosorbent assay was developed to detect chicken anti-rovirus antibodies. Studies of the parameters which affect the outcome of the assay with avian serum revealed two aspects for a successful assay. First, enzyme-antibody conjugates prepared by the periodate oxidation technique were found to have retained far more immunological activity than conjugates produced by a glutaraldehyde cross-linking. Second, the results indicated an unusually high affinity of chicken immunoglobulin for the microplate plastic which was mostly eliminated by a pretreatment technique with fixed fetal calf serum. The enzyme-linked immunosorbent assay compared favorably with the latex passive agglutination test, yielding a titration endpoint of 1:511,000, or approximately 1,300 times more sensitive than the latex passive agglutination assay. The assay proved not only to be sensitive to less than 1 ng of specific antibody, but also to have low to moderate variance and high reliability.

Animals↗
PubMed1979

Acid alpha-naphthyl acetate esterase: presence of activity in bovine and human T and B lymphocytes.

Non-specific acid alpha-naphthyl acetate esterase (ANAE) activity was demonstrated in a majority of bovine peripheral blood lymphocytes, confirming and extending the observations on murine and human lymphocytes made by previous workers. Simultaneous study of both ANAE activity and spontaneous erythrocyte (E) or erythrocyte-antibody-complement (EAC) rosetting capability of the same bovine lymphocytes showed directly that, while 64.2 +/- 4.6 (SEM) % of bovine lymphocytes capable of forming E rosettes were ANAE positive, 38.3 +/- 0.8% of those forming EAC rosettes were also ANAE positive. Similar studies of human peripheral blood lymphocytes showed also that, while 80.6 +/- 2.2% of the lymphocytes capable of forming E rosettes were ANAE positive, 44.1 +/- 2.6% of EAC forming lymphocytes were ANAE positive. Thus the presence of ANAE activity in a majority of T lymphocytes and a significant proportion of B lymphocytes of both human and bovine peripheral blood is indicated. Human and bovine lymphocytes from phytohaemagglutinin (PHA)-stimulated cultures demonstrated greatly enhanced intensity of ANAE activity.

Animals↗
PubMed1978

Lymphocyte response to phytohemagglutinin: temporal variation in normal dogs.

The lymphocyte response to mitogens is frequently used as a screening method for monitoring general immunocompetence. In practice, however, the technique is potentially misleading. The results presented here suggest that temporal variation in lymphocyte response is the norm. Considerable variation in response to phytohemagglutinin was found for several dogs tested over different time periods. The response for any individual dog also fluctuated whether testing was at 2-week intervals, daily, or even every 4 h. This temporal variation remained whether separated lymphocytes or whole blood was cultured and when the results were expressed on a per lymphocyte basis. This suggests that there is a real difference in the response capability of individual lymphocytes. Factors affecting the numbers of leukocytes and the proportions of different types of lymphocytes in the peripheral blood are suggested as a possible source of the variation. Because of the inherent variation in lymphocyte responsiveness, it is necessary to test at different intervals to obtain an accurate indication of the general status of an individual's immunocompetence and to determine the time of peak response capability for that individual.

Animals↗