Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spleen cells of B6 mice not previously immunized were induced to DNA synthesis by supernatants from HSV-infected tissue culture. The stimulatory principle could be passed through a 45-micrometer filter and sedimented at 100,000 x G. It was abolished by UV light, heating at 56 degrees C, and by an anti-HSV serum. The possibility that the observed stimulation was caused by LPS was therefore excluded, and there was a-so no indication of mycoplasma contamination. Partial purification of spleen cells from macrophages resulted in an increased stimulation by HSV. From experiments with nylon columns, anti-theta antibody, and nude mice it was concluded that HSV acted as a B cell mitogen. Strains of both HSV types 1 and 2 were stimulatory for B6 spleen cells. Of nine freshly isolated HSV strains with identical passage history (twice in HEF) four were strongly stimulatory, three showed a moderate stimulation, and two did not stimulate. Spleen cells from A/J and DBA/2 mice were stimulated to the same extent by HSV (WAL) as spleen cells from B6 mice. No viral replication was demonstrable in B6 spleen cell cultures stimulated for DNA synthesis by HSV. Thus our study demonstrates induction of cellular DNA synthesis in B lymphocytes by HSV which is abolished by inactivation of the virus.
 ...
PMID:In vitro mitogenic stimulation of murine spleen cells by herpes simplex virus. 20 55

Heat-inactivated A. laidlawii (AL) was found to be a potent mitogen for mouse spleen cells. Spleen cells from homozygous nude mice and spleen cells treated with anti-theta serum and complement responded as well as their respective controls, indicating that AL represented a B-cell mitogen for mouse spleen cells. Spleen cells from LPS-unresponsive C3H/Hej mice responded well to AL. The peripheral blood leucocytes from unselected human donors were also stimulated by AL, which appeared to represent a T-cell mitogen for human leucocytes. However, the possibility that it acted as a specific antigen could not be excluded. Attention was drawn to the possibility that the presence of mycoplasma might considerably affect the results of tests where tissue-culture cells or derivatives thereof are added to leucocyte cultures.
 ...
PMID:Effect of A. laidlawii on murine and human lymphocyte cultures. 89 Oct 34

Parenteral immunization of C3H mice with viable Mycoplasma pulmonis organisms protected them from pneumonia induced by intranasal inoculation of these organisms. Spleen cells obtained from immunized mice were ineffective in preventing syngeneic recipients from developint respiratory disease. In contrast, convalescent-phase serum enhanced the clearance of mycoplasmas from the respiratory tract of mice challenged with a small number of organisms. Further, although 'immune' serum had no detectable effect on the number of mycoplasmas in the respiratory tract of mice challenged with a large number of organisms, such animals did not develop pneumonia. Since the pneumonia appears to be the results of the host's immune response to the mycoplasma, it is suggested that the transferred 'immune' serum may act by suppressing the immune response so that mice develop less severe lung lesions. This suggestion is supported by the observation that the complement-fixing antibody response of passively immunized mice was suppressed.
 ...
PMID:Effects of active and passive immunization on Mycoplasma pulmonis-induced pneumonia in mice. 127 33

Temperature-sensitive mutant vaccines protect rats against Mycoplasma pulmonis infection. The role of the humoral or cellular immune response in resistance to mycoplasma infection was investigated by adoptive-transfer experiments. Spleen cells from Lewis rats vaccinated but not challenged with wild-type organisms (vaccinated) and spleen cells from rats vaccinated (or not) and challenged were effective in preventing syngeneic recipients from developing respiratory disease. There was also a significant reduction in the incidence and number of challenging organisms in the respiratory system. In contrast, sera from the same donors had no detectable effect on the number of mycoplasmas recovered or on lesion development in the respiratory tract. We conclude that cellular immunity rather than humoral immunity generated in vaccinated rats confers protection against subsequent infection.
 ...
PMID:Vaccination of Lewis rats with temperature-sensitive mutants of Mycoplasma pulmonis: adoptive transfer of immunity by spleen cells but not by sera. 198 49

Our understanding of the mechanisms involved in B cell activation, proliferation and differentiation to immunoglobulin secreting cells has been facilitated by the use of T-independent and T-dependent antigens. The majority of these studies have used the murine system and only recently, the rat. Because membranes isolated from Mycoplasma neurolyticum are potent B cell mitogens in the rat and some T-independent antigens also activate DNA synthesis in B cells, the in vitro and in vivo antibody responses induced by M. neurolyticum membranes in T-deficient rat systems were examined. The three groups of rats used, i.e., nude; anti-thymocyte serum-treated, neonatally-thymectomized (ATS-Tx); and normal Fischer 344 produced a non-polyclonal antibody response against the membranes. Spleen cell cultures that were T cell deficient and B cell enriched produced plaque-forming cells against the Mycoplasma membranes. Antibody production was depleted upon removal of Sephadex G-10 adherent cells. The antibody response is comprised of both antigen-specific and polyclonal responses. Lipoglycan, found in the aqueous phenol extract of the membranes, is the mitogenic fraction of the membranes, and this study suggests that it may also be the T-independent antigenic component of the M. neurolyticum membranes.
 ...
PMID:Mycoplasma neurolyticum membranes: a T-independent antigen in the rat. 242 52

Spleen cells derived from rats naturally-infected with Mycoplasma pulmonis were stimulated in vitro, and then fused with a mouse myeloma cell line. The resulting hybridomas were screened for mycoplasma-specific Mabs by ELISA and for hemolysis-blocking activities. Fusions performed with in vitro-treated spleen cells yielded larger numbers of growth-positive wells and antibody secreting cells than untreated spleen cells from the same animals. Hybridomas derived from naturally-infected animals gave a higher percentage of hemolysin-specific monoclonal antibodies than did hyperimmunized animals. This indicated that B cell priming during mucosal infections can produce antigen-primed spleen cells. Stimulation of these cells in vitro can result in monoclonal antibodies against antigens not normally recognized during immunization with in vitro grown pathogenic bacteria.
 ...
PMID:In vitro stimulation of nonimmunized, naturally infected rat spleen cells for the production of Mycoplasma pulmonis-specific monoclonal antibodies. 280 12

A new disease in broiler breeders known in Australia as Big Liver and Spleen Disease (BLS) is described from field observations, retrospective record analysis, and detailed study of a selected flock. BLS has a predilection for adult birds. It is characterized clinically by a sudden drop in egg production, splenomegaly, hepatomegaly, and increased mortality and histologically by a period of lymphoproliferation followed by a period of lymphoid destruction that coincides with the clinical signs. Epidemiology suggests an infectious cause, though initial attempts at isolation of a causative agent have been unsuccessful, and it is serologically distinct from the common avian viral and mycoplasma diseases.
 ...
PMID:An egg drop associated with splenomegaly in broiler breeders. 320 73

Two experiments were conducted with broiler chicks to study the effects of posthatch holding time in the incubator on physiological and disease parameters. In each experiment, half of the chicks were removed shortly after hatching and half of the chicks were allowed to remain in the hatcher for an additional 30 hr. Bursa weights, hematocrits, total plasma protein, and blood glucose concentrations were measured at various times up to 35 and 28 days of age in Experiments 1 and 2, respectively. In addition, chicks hatched from eggs with one of two specific gravities (less than or equal to 1.065 and greater than or equal to 1.075) were tested in the second experiment. Spleen weights, heterophil:lymphocyte ratios and the influence of an aerosol Newcastle disease-Mycoplasma gallisepticum vaccine challenge were also measured in the second experiment. In Experiment 1, when chicks were held in the hatcher for an additional 30 hr, bursa weights were reduced through 8 days of age; however, they were significantly heavier by 21 days of age. In Experiment 2, both bursa and spleen weights were significantly reduced through 14 days of age when chicks were held in the incubator. Total plasma protein and glucose concentrations, hematocrits, and heterophil:lymphocyte ratios were all significantly higher for chicks held in the incubator. Chicks held in the incubator and then exposed to an aerosol vaccine challenge at 1 day of age had a significantly greater percentage of air sac lesions and the lesions were more severe at 28 days of age. Egg specific gravity had no influence on any of the parameters measured.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Influence of hatcher holding times on several physiological parameters associated with the immune system of chickens. 382 96

Culture fluid (CF) from LA cells (LA-CF) strongly stimulated the proliferation of normal A/J mouse spleen cells in vitro. This activity was nondialyzable, labile to 56 degrees C for 20 min., sedimentable, H-2 and species unrestricted, and was found to be mycoplasma-derived. LA-CF was active for B cells because in vitro treatment of A/J spleen cells with anti mouse Ig antiserum and complement eliminated their responsiveness to LA-CF. LA-CF stimulated the resting, small spleen cells of the nude mouse as strongly as lipopolysaccharide (LPS) did. Spleen cells of the X chromosome-linked immunodeficiency (Xid) mouse were stimulated by LPS to a half of the control mice, and by LA-CF to a quarter of the control. LPS-low responder (C3H/HeJ) spleen cells were also stimulated by LA-CF. The mycoplasma(s)-derived B cell mitogen in the LA-CF was different from LPS.
 ...
PMID:Comparison of mycoplasma(s)-derived B cell mitogenic activity with lipopolysaccharide. 390 4

In this study, Sprague-Dawley rats were exposed in a TEM chamber to 20-MHz (HF-band) continuous-wave radiofrequency radiation (RFR) for 6 hr/day, 5 days/week up to 6 weeks. The average E-field intensity was 2686 +/- 164 V/m (mean +/- SD) and the calculated specific absorption rate was 0.3 W/kg. Randomly sampled rats killed on Days 8, 22, 39, and 42 after initiation of exposure showed no statistically significant differences from controls for body mass, spleen cell density, erythrocyte and leukocyte counts, hematocrit, hemoglobin, methemoglobin, erythrocyte fragility, bilirubin, creatinine, SGPT, alkaline phosphatase, calcium, sodium, potassium, and spleen cell chemiluminescence. Splenic mass differences were statistically significant (p less than 0.05) only on Day 22. Spleen to body mass ratios differed significantly between exposed and control groups on Days 22 and 39 (P less than 0.05 and P less than 0.025, respectively). Histologic examination of the rats revealed the successive accumulation of phagocytic cells, lymphoid proliferation, development of lesions, and tissue necrosis characteristic of respiratory mycoplasmosis. In a followup experiment, a separate set of rats was exposed for 6 weeks to identical levels of RFR. No significant differences were found in splenic parameters and spleen cell peroxidative activity. Histologic examination of these animals revealed no evidence of mycoplasma infection. The observed differences between exposed and control animals of the first experiment appear to have resulted from subclinical respiratory mycoplasmosis rather than exposure to RFR.
 ...
PMID:Effects of 20-MHz radiofrequency radiation on rat hematology, splenic function, and serum chemistry. 402 74


1 2 3 Next >>