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V K Tsiagbe

Publications and source records attributed to V K Tsiagbe.

30 records · Page 2Linked to original sources
PubMed1990

Germinal center cells are a major IL-5-responsive B cell population in peripheral lymph nodes engaged in the immune response.

Germinal center formation and the development of B cell memory in lymphoid tissue is a T cell-dependent process. The specific B cell-T cell interactions, and/or cytokines, resulting in germinal center cell growth have not yet been identified. Germinal center B cells were separated from other lymph node (LN) B cells by panning on peanut agglutinin (PNA)-coated dishes. Resulting fractions enriched for PNA+ (germinal center) B cells, and the PNA- (other) LN B cells from immune SJL mice were assayed for proliferation in the presence of cytokines. PNA+ and PNA- B cells responded equally to IL-4 in the anti-mu co-stimulator assay. In contrast, PNA+ B cells responded to murine (r)IL-5 or human B cell growth factor in the dextran sulfate (DxS) co-stimulator assay, to a much greater degree than did PNA- B cells. The same results were obtained with PNA+ and PNA- cells from LAF1 mice. Unfractionated LN B cells from nonimmunized SJL or BALB/c mice did not respond to IL-5 with or without DxS. B cell populations from BALB/c mice such as from spleen and peritoneal cavity, which are known to be high in Ly-1+B cells, responded to IL-5 alone, and more dramatically, to IL-5 as a co-stimulator with DxS. Such populations of cells from SJL mice, which are known to contain low numbers of Ly-1+B cells, responded markedly less. These results are consistent with those of others which show that in nonimmunized mice, Ly-1+B cells are a major IL-5 responsive subpopulation. IL-1 enhanced the proliferation of PNA+ cells in response to rIL-5 and had no effect on PNA- cells. IL-4 and IL-5 did not enhance each other's effects as co-stimulators of proliferation. In contrast to PNA+ B cells from immune LN, B cells activated by Escherichia coli endotoxin exhibited no responses to rIL-5. The present results indicate that in immune LN, PNA+, germinal center B cells constitute a prominent IL-5-responsive population.

Animals↗
PubMed1990

Proliferative response of T cells from tumor-immune chickens to carcinogen-induced fibrosarcoma cells.

Immunity to carcinogen-induced transplantable fibrosarcomas (CHCT-NYU-4, -97, -36 and -20) in SC chickens was studied by the ability of spleen cells from NYU-4 or -97 immune chickens to proliferate in response to tumor cells in vitro. Spleen, but not peripheral blood cells, from NYU-4 immune chickens proliferated significantly more vigorously to gamma-irradiated NYU-4 cells than did cells from normal chickens. The proliferative response was not much affected by addition of indomethacin. Spleen cells from NYU-4-immune agammaglobulinemic (A gamma) chickens exhibit the same ability to proliferate in presence of gamma-irradiated NYU-4 tumor cells. Analysis of the phenotype of the T-cell component involved in proliferation showed that the proliferative response was significantly decreased by removal of CT4+ cells through indirect panning. Removal of CT8+ cells enhanced background proliferation without affecting the total thymidine incorporation in the presence of tumor cells. Immune spleen cells usually gave highest responses to the immunizing tumor, but also exhibited cross-reactivity to cells from other individual tumors induced by the same carcinogen.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

Paraproteins and primary lymphoma in SJL mice. I. Individuality of idiotypes on paraproteins.

The isotype distribution and idiotypic determinants of paraproteins (PP) found in sera from aging SJL mice were studied. One or more PP were found in 79% of 9-11 month old mice; the isotypes were gamma 1 greater than or equal to alpha greater than or equal to gamma 2a much greater than gamma 3 much greater than gamma 2b. There was a significant tendency for the PP to occur in pairs or triplets, multiple PP being found in 35% of the mice without an evident association between any two isotypes. Rabbit anti-Id was prepared against four isolated PP, two gamma 1 and two gamma 2a. Inhibition of anti-Id-Id interaction was specific for the immunizing PP only and was absent with all other PP studied (8 gamma 1 and 10 gamma 2 PP) and with normal SJL Ig. It is concluded that SJL PP fail to exhibit cross-reactive idiotypes and show a wider range of isotype distribution than was previously suspected, although PP of mu, delta, and epsilon isotypes are absent.

Animals↗
PubMed1990

Paraproteins and primary lymphoma in SJL mice. II. Primary lymphomas do not produce paraprotein.

The incidences of Ig paraprotein (PP) and reticulum cell sarcomas (lymphomas) were studied in a group of 75 SJL mice, 9-11 months of age. PP and lymphoma were observed in 52% of the mice. PP alone was observed in an additional 27% and lymphoma alone in an additional 11% of mice. In attempts to establish a causal relationship between lymphomas and PP, three approaches were used: (a) Serum PP levels were followed during lymphoma growth in primary lymphoma bearing mice and found to decrease rather than to increase. (b) Recipients of primary transplants were examined for appearance of PP-related idiotypes (Id) in their sera and for lymphoma growth. The Id appeared early (Day 10-11) and then disappeared, while lymphoma growth usually was detectable by greater than or equal to 1 month. (c) One of the primary lymphomas was propagated as a tissue culture line and found not to produce any PP or intact Ig. It is concluded that the PP of SJL mice are not produced by their lymphomas. Other possible relationships are discussed, including the role of the PP as a symptom of a prelymphomatous stage that develops in a very high percentage of SJL mice.

Animals↗
PubMed1988

Alterations in phospholipid composition of egg yolks from laying hens fed choline and methionine-supplemented diets.

A trial was conducted to assess the effects of choline and methionine supplementation of the diets of hens on phospholipid composition of egg yolk. By chemical analysis, the basal diet contained 16.6% protein, 1,041 parts per million (ppm) of choline, and .53% TSAA. The energy level was 2,899 kcal ME/kg diet, with no added fat. A rapid isocratic HPLC procedure using a Waters mu Bond-NH2 column (Waters Associates, Milford, MA) was developed to quantify phospholipid components. Analysis of egg samples at peak production (36 wk of age) showed significant (P less than .05) elevations in total phospholipids, phosphatidylcholine (PC), and the ratio of PC to phosphatidylethanolamine (PE), when choline was added at 500 or 1,000 ppm. Phosphatidylethanolamine, in contrast, showed a decline with choline supplementation. Methionine supplementation (125 to 250 ppm) also caused elevations in the total phospholipid composition of the egg yolk but had only modest effects on PC and PE. There was a significant (P less than .05) correlation between the yolk weight and total phospholipid concentration, PC, and the PC:PE ratio. There was a relationship between phospholipid content and weight of eggs when diets of laying hens were supplemented with choline.

Animals↗
PubMed1987

Identification of volatile sulfur derivatives released from feathers of chicks fed diets with various levels of sulfur-containing amino acids.

Physical changes are observed in the feathers of chickens fed diets with high levels of methionine or cysteine. Chicks were fed diets chemically analyzed to contain 21% crude protein, 0.35% methionine and 0.37% cystine (basal) supplemented with DL-methionine [0.063 (control), 0.25 or 1.45%] or L-cysteine (0.203%). At 3 wk of age, the birds were weighed and the feathers scored for softness. Feather strength (i.e., force-displacement curves) was determined on feathers from the pectoral tract. A significant (P less than 0.05) reduction in body weight and an increase in feather softness were seen when chicks fed the control diet and those fed the diet with 1.45% added methionine were compared. Chicks fed the diet supplemented with 0.203% L-cysteine produced the strongest feathers; those fed diets supplemented with 1.45% DL-methionine produced the weakest feathers. Volatile sulfur compounds released from the feathers were trapped as dinitrophenyl (DNP) thioethers and were analyzed by thin-layer chromatography, high pressure liquid chromatography and mass spectrometry. More bound sulfide (P less than 0.05) was recovered from feathers of chickens fed the diet supplemented with 1.45% methionine than from feathers of chickens fed the other diets. The feather softness score was correlated (r = 0.5; P less than 0.05) with bound sulfide. Thus, consumption of a diet with a level of methionine that is approximately three times the requirement resulted in decreased growth, elevated sulfide bound to the feathers and soft, weak feathers.

Amino Acids, Sulfur↗
PubMed1987

Efficacy of cysteine in replacing methionine in the immune responses of broiler chicks.

Two trials were conducted to compare the effects of supplements of methionine and cysteine on the growth and immune responses of broiler chicks fed corn-soy diets. The basal diet contained 21% crude protein, 3,255 kcal metabolizable energy/kg diet, .35% methionine, .37% cysteine, and .13% choline. Additions to the basal diet were methionine (.063, .25, .85, and 1.45%), or cysteine (.203%), or a combination of methionine (.063%) and cysteine (.153%). Total antibody and 2-mercaptoethanol-resistant antibodies, immunoglobulin G (IgG), were determined in chicks inoculated intraperitoneally at 14 days of age and serially bled at 4, 7, and 10 days postinoculation. Thymus-derived (T)-cell-dependent in vivo mitogen response to phytohemagglutinin-P (PHA-P) was assessed via wing web swelling. The methionine requirement for growth (0 to 3 wk of age) was found to be no more than .413% of the diet (.35% in the basal diet plus .063% added). Addition of 1.45% methionine to the basal diet resulted in significant depression (P less than .05) in growth. The antibody responses generally peaked at 7 days postprimary inoculation. Both methionine and cystine supplementation at low levels resulted in improvement in the cell mediated PHA-P responses as well as in the IgG (T-cell-dependent) responses. High supplemental methionine (1.45%), however, caused significant (P less than .05) depressions in both responses. Equimolar additions of methionine and cysteine (16.8 mmol/kg diet) showed that cysteine was about 84 and 70% as efficacious as methionine in the IgG and the PHA-P stimulation (PHA-I), respectively, in healthy chicks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Enhanced immune responses in broiler chicks fed methionine-supplemented diets.

Effects of feeding supplementary methionine and choline on broiler growth and immunity were examined by supplementing a corn-soybean diet that contained 21% crude protein, 3,255 kcal metabolizable energy/kg diet, .35% methionine, .37% cystine, and .13% choline. Methionine (.063, .125, .25%) and choline (.125, .25%) were dietary variables. Sulfate (.055%) was added either alone or along with methionine (.125 or .25%) and choline (.125%). In one study, the .25% methionine diet was supplemented with .121% betaine. Sodium and chloride levels were constant in all the diets. Feed and distilled water were supplied ad libitum. Total antibodies, immunoglobulin (Ig) G (2-mercaptoethanol-resistant antibodies) and IgM (2-mercaptoethanol-sensitive antibodies) were determined in 3-wk-old chicks inoculated intraperitoneally with sheep red blood cells. The thymus-derived (T)-cell-dependent in vivo mitogen response to phytohemagglutinin-P (PHA-P) was assessed via wing web swelling. The methionine requirement for growth (0 to 3 wk of age) was approximately .413% of the diet (.35% in the basal diet plus .063% added). Supplementation of the basal diet with .125% choline stimulated growth to the same extent as did the extra .063% of methionine. Addition of .055% sulfate with .125% choline did not improve the ability of the latter to spare methionine. Supplemental methionine resulted in significant (P less than .05) dose-related increases in total antibody, IgG, and response to the mitogen PHA-P, but not in IgM. There were no effects of choline on the immune variables studied. These results suggest that methionine is required for select components of the antibody response, which effect might be related to T-cell help.

Animals↗
PubMed1987

Assessment of softness properties of feathers.

An instrument to be called the "Crimp Meter" was designed and used with a conventional balance to enable the plotting of a force-displacement curve for individual feathers. A comparison of the curves described by different feathers was made by regression analysis. The type of curve described by a feather is characteristic of its tensile properties and its degree of softness. This procedure was employed to objectively confirm the observation that chicks fed toxic levels of methionine (1.45% added) in corn-soybean diets had significantly softer (P less than .001) feathers than those fed nontoxic levels of cysteine (.203% added). The basal diet was analyzed and found to contain .35% methionine and .37% cystine. This device had potential for the down-feather, wool, and fabric industries.

Animals↗
PubMed1987

Critical vitamin supplementation of broiler diets high in alfalfa juice protein.

Three trials were conducted to identify the critical vitamins in the diets of broiler-strain chicks fed alfalfa juice protein concentrate (AJPC) corn-soy diets from 0 to 3 wk of age. Vitamin supplements were added to AJPC diets. Diets were formulated to contain, parts 30/121, 40/128, 50/135, and 60/142 parts AJPC/parts total diet. Parts were used to permit usage of wet materials and still maintain about 90% dry matter. All diets were formulated to contain 20% crude protein, .93% total sulfur-containing amino acids, and 2,940 kcal metabolizable energy/kg diet. Propionic acid was added at .2% to all diets. Feeds were refrigerated (7 C) and fed out daily. The addition of choline, riboflavin, vitamin B12, vitamin A or E, folic acid, or biotin did not increase weight gains. Addition of 3 mg/kg vitamin B6 completely overcame the growth depression caused by the 50-parts AJPC diet and significant (P less than .05) growth increases (13 to 29%) were achieved with vitamin-B6 supplementation to the 60-parts AJPC diet. Depressed immune responses were completely prevented by the addition of 3 mg/kg of vitamin B6. The significant (P less than .05) increases in leg deformities observed in birds fed the 60-parts AJPC diet were also brought back to more typical values in birds fed the diet supplemented with 3 mg/kg vitamin B6. Vitamin K supplementation (.53 mg/kg) to the 60-parts AJPC diet resulted in significant decreases from 15 min in blood clotting times to 3 to 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1982

The effect of choline supplementation in growing pullet and laying hen diets.

Two experiments were conducted to determine the effect of choline supplementation on corn-soy-meat-based grower and laying hen diets. Diets contained 2.5% and 3% meat and bone meal in the growing and laying diets, respectively, and on chemical analysis contained 1005 and 1041 ppm of choline respectively. In the first experiment, 1000 ppm of choline were added to the basal growing and laying diets, and in the second experiment the laying diet was supplemented with 550 ppm or 1000 ppm of choline. In both trials, choline supplementation did not increase gains or feed efficiency for pullets from 8 to 20 weeks. However, choline supplementation during the laying period resulted in a statistically significant improvement of egg production and egg size. Supplementation of choline in the growing phase did not affect the laying performance. Laying performance was not improved by 2 micrograms/kg of supplementary vitamin B12 in a 1000 ppm choline supplement diet (78% vs. 76% hen-day production). In the second trial, added levels of choline (0, 500, and 1000 ppm) resulted in egg production from 24 to 64 weeks of 73, 76, and 76% hen-day production, respectively. Egg weights were 59, 61, and 61 g, respectively. This suggests that the total choline requirement of laying hens on a corn-soy-meat diet, and in absence of supplementary methionine, is greater than 1000 ppm but no more than 1500 ppm.

Animals↗