scholarly journals Pokeweed Mitogen

2020 ◽  
Author(s):  
Keyword(s):  
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.


Author(s):  
J. Jacob ◽  
M.F.M. Ismail

Ultrastructural changes have been shown to occur in the urinary bladder epithelium (urothelium) during the life span of humans. With increasing age, the luminal surface becomes more flexible and develops simple microvilli-like processes. Furthermore, the specialised asymmetric structure of the luminal plasma membrane is relatively more prominent in the young than in the elderly. The nature of the changes at the luminal surface is now explored by lectin-mediated adsorption visualised by scanning electron microscopy (SEM).Samples of young adult (21-31 y old) and elderly (58-82 y old) urothelia were fixed in buffered 2% glutaraldehyde for 10 m and washed with phosphate buffered saline (PBS) containing Ca++ and Mg++ at room temperature. They were incubated overnight at 4°C in 0.1 M ammonium chloride in PBS to block any remaining aldehyde groups. The samples were then allowed to stand in PBS at 37°C for 2 h before incubation at 37°C for 30 m with lectins. The lectins used were concanavalin A (Con A), wheat germ agglutinin (WGA), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) at a concentration of 500 mg/ml in PBS at pH 7.A.


2000 ◽  
Vol 70 (3) ◽  
pp. 92-101 ◽  
Author(s):  
Burim Ametaj ◽  
Brian Nonnecke ◽  
Ronald Horst ◽  
Donald Beitz

Individual and combined effects of several isomers of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on interferon-gamma (IFN-gamma) secretion by blood mononuclear leukocytes (MNL) from nulliparous and postparturient Holstein cattle were evaluated in vitro. In the first experiment, effects on incubation period (24 to 72 hours) and time of supplementation (0 to 32 hours) with all-trans, 9-cis, 13-cis-, and 9,13-dicis-RAs (0 to 100 nM) on IFN-gamma secretion by pokeweed mitogen (PWM)-stimulated (0 and 10 mug/ml) MNL from nulliparous cattle were evaluated. In the second experiment, MNL from postparturient cows (bled at 0, 2, 4, and 16 days postpartum) were stimulated with PWM (0 and 10 mug/ml) in the presence of RA isomers (9-cis- or 9,13-dicis-RA; 0 to 100 nM), 1,25-(OH)2D3 (0 to 100 nM), or with combinations of these metabolites. The results show that individual isomers of RA had no effect on IFN-gamma secretion by PWM-stimulated MNL from nulliparous or postparturient cows. Furthermore 1,25-dihydroxyvitamin D3 inhibited IFN-gamma secretion by MNL from nulliparous and postparturient dairy cows; however, the degree of inhibition was greater when 9-cis- and 9,13-dicis-RA were also present in the cultures. Finally mononuclear leukocytes from postparturient dairy cows produced substantially less IFN-gamma than did MNL from nulliparous cattle. It is concluded that retinoic acids individually did not affect the capacity of leukocytes from dairy cattle to secrete IFN-gamma. This result is in marked contrast to studies in monogastric species indicating that RAs inhibit IFN-gamma secretion by peripheral blood T cells. Inhibition of IFN-gamma secretion by 1,25-(OH)2D3 was potentiated by 9-cis- and 9,13-di-cis-retinoics acids, suggesting that an excess of dietary vitamins A and D may compromise further the naturally immunosuppressed postparturient dairy cow. Additional research is necessary to determine if the combined effects of these metabolites on IFN-gamma secretion represent an increased susceptibility of the dairy cow to infectious diseases during the periparturient period. Lower secretion of IFN-gamma by MNL from postpartutient dairy cows, relative to nulliparous cattle, suggests that recently-calved cows are naturally immunosuppressed.


1993 ◽  
Vol 22 (2-3) ◽  
pp. 147-153
Author(s):  
Ana M. Llano ◽  
Juan P. Amieiro‐Puig ◽  
Edmundo N. Kraiselburd ◽  
Matthew J. Kessler ◽  
Carlos A. Málaga ◽  
...  

1986 ◽  
Vol 249 (2) ◽  
pp. 596-604 ◽  
Author(s):  
Ryotaro Yoshida ◽  
Tohru Oku ◽  
Jiro Imanishi ◽  
Tsunataro Kishida ◽  
Osamu Hayaisi

2007 ◽  
Vol 99 (4) ◽  
pp. 793-805 ◽  
Author(s):  
Dennis F. Lawler ◽  
Brian T. Larson ◽  
Joan M. Ballam ◽  
Gail K. Smith ◽  
Darryl N. Biery ◽  
...  

This report reviews decade two of the lifetime diet restriction study of the dog. Labrador retrievers (n 48) were paired at age 6 weeks by sex and weight within each of seven litters, and assigned randomly within the pair to control-feeding (CF) or 25 % diet restriction (DR). Feeding began at age 8 weeks. The same diet was fed to all dogs; only the quantity differed. Major lifetime observations included 1·8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis. Long-term DR did not negatively affect skeletal maturation, structure or metabolism. Among all dogs, high static fat mass and declining lean body mass predicted death, most strongly at 1 year prior. Fat mass above 25 % was associated with increasing insulin resistance, which independently predicted lifespan and chronic diseases. Metabolizable energy requirement/lean body mass most accurately explained energy metabolism due to diet restriction; diet-restricted dogs required 17 % less energy to maintain each lean kilogram. Metabonomics-based urine metabolite trajectories reflected DR-related differences, suggesting that signals from gut microbiota may be involved in the DR longevity and health responses. Independent of feeding group, increased hazard of earlier death was associated with lower lymphoproliferative responses to phytohaemagglutinin, concanavalin A, and pokeweed mitogen; lower total lymphocytes, T-cells, CD4 and CD8 cells; lower CD8 percentages and higher B-cell percentages. When diet group was taken into account, PWM responses and cell counts and percentages remained predictive of earlier death.


1974 ◽  
Vol 140 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Melvyn Greaves ◽  
George Janossy ◽  
Michael Doenhoff

Human lymphocytes from spleen and tonsils have been cultured with a variety of polyclonal mitogens. Cultures consisted of either unseparated T and B cells or alternatively purified T or B lymphocytes. The purity of the starting cell populations and the origin of activated lymphoblasts was analyzed with a panel of seven markers which discriminate between T and B cells. The selectivity of the lymphocyte responses was influenced by cell populations in a given culture, the mitogen used, and to a limited extent on culture conditions. Purified T lymphocytes from tonsil and spleen responded to phytohemagglutinin (PHA), pokeweed mitogen (PWM), and staphylococcal enterotoxin B (SEB). Purified B cells from spleen responded well to PWM, weakly to SEB and lipopolysaccharide, but not at all to PHA. Tonsil B cells responded weakly to PWM and SEB but not to PHA. Some B lymphocytes do respond to PHA in the presence of activated T cells. These results are discussed in relation to previously reported selective responses of human cells and parallel studies in animal species.


1982 ◽  
Vol 55 (3) ◽  
pp. 355-360 ◽  
Author(s):  
James M. Seltzer ◽  
Richard D. O'Connor ◽  
Ronald A. Simon ◽  
Tony E. Hugli
Keyword(s):  

1999 ◽  
Vol 96 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Moacir WAJNER ◽  
Kátia D. SANTOS ◽  
Jeanine L. SCHLOTTFELDT ◽  
Maureen P. ROCHA ◽  
Clóvis M. D. WANNMACHER

Recurrent infections are common features in patients affected by propionic acidaemia (McKusick 232000) and methylmalonic acidaemia (McKusick 251000). Since these disorders are biochemically characterized by tissue accumulation of propionic acid and methylmalonic acid respectively, it is possible that these compounds may act as immunosuppressants. We therefore investigated the effect of propionate and methylmalonate on cellular growth of human peripheral lymphocytes stimulated in vitro by phytohaemagglutinin, concanavalin A and pokeweed mitogen, a recognized test of cellular immunocompetence. Lymphocytes were cultured in flat-bottomed 96-well microplates at 37 ;°C for 96 ;h (phytohaemagglutinin and concanavalin A) or 144 ;h (pokeweed mitogen) in the presence of one mitogen at different concentrations and of one acid added at doses of 1.0, 2.5 or 5.0 ;mM. Cell blastogenesis was measured by the incorporation of tritiated thymidine into cellular DNA and compared with that of identical cultures with no acid added (controls). A consistent and progressive inhibitory effect of propionic acid with increasing concentrations in culture was identified with all mitogens and was more pronounced with pokeweed mitogen. Lymphocyte blastogenesis was not altered in the presence of methylmalonic acid. The effect of propionate was observed only when the drug was added at the beginning (phytohaemagglutinin-activated) or until 24 ;h (concanavalin A- and pokeweed mitogen-activated) of culture. The viability of lymphocytes after treatment with the drug, as assessed by the Trypan Blue exclusion test, revealed no change when compared with the same untreated lymphocytes, indicating no lymphocytotoxic activity. In conclusion, propionic acid, which accumulates in tissues of patients with propionic acidaemia, causes ‘in vitro’ immunosuppression, which may be related to the recurrent infections characteristic of these patients.


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