Immunostimulating effects of sugar cane extract on X-ray radiation induced immunosuppression in the chicken.

The present study was undertaken to evaluate the effect of sugar cane (Saccharum officinarum L.) extract (SCE) on the immune system of X-ray immunosuppressed chickens. SCE (500 mg/kg/day) was administrated into the crop of 3-week-old chickens for three consecutive days before or after irradiation. The results indicated that administration of SCE before or after whole body X-ray irradiation enhanced both primary and secondary immune responses in chickens immunized with sheep red blood cells and Brucella abortus (BA) as well as cell-mediated immunity measured by delayed type hypersensitivity to human gamma-globulin.

Apoptosis in the chicken bursa of fabricius induced by X-irradiation.

Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, reaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

Loss of cell cycle controls in apoptotic lymphoblasts of the bursa of Fabricius.

Lymphoblasts of the normal embryonic follicles of the chicken bursa of Fabricius undergo rapid apoptosis when exposed to gamma-radiation or when cell-cell contacts are disrupted by mechanical dispersion in short term culture. We have observed previously that overexpression of v-myc sensitizes preneoplastic bursal lymphoblasts to induction of cell death, whereas resistance to induced cell death is acquired during progression to neoplasia. In this study we observed extensive DNA degradation in the large majority of the lymphoblast population within the first hour after dispersion-induced apoptosis. Paradoxically these cells continued to progress into S-phase with the bulk of DNA cleavage and death occurring in S-phase cells (i.e., in cells with more than 2C and less than 4C DNA content). We confirmed the S phase status of apoptotic cells by determining that detection of nuclear cyclin A in individual cells also corresponded with detection of DNA breakage. Levels of cyclin E, cyclin E-dependent H1 histone kinase, and p53 proteins were maintained during dispersion-induced DNA cleavage. gamma-radiation failed either to inhibit cell cycle progression or to raise p53 levels in dispersed bursal lymphoblasts. In intact bursal follicles low doses of gamma-radiation induced p53 whereas higher, apoptosis-inducing doses failed to induce p53 or prevent G1 to S-phase progression. These results suggest that normal DNA damage-induced cell cycle checkpoint controls are lost or overridden when apoptosis is induced in bursal lymphoblasts.

[The action of gamma irradiation on the luminol-dependent chemiluminescence of activated thymocytes]. / Deistvie gamma-oblucheniia na liuminolzavisimuiu khemiliuminestsentsiiu aktivirovannykh timotsitov.

The method of luminol-dependent chemiluminescence was used to study the affect of gamma radiation on activation of cells of thymus and bursa of Fabricius upon their adhesion on kapron. Thymocyte activation by adhesion on glass or kapron provoked chemiluminescence which was connected with the development in cells of active oxygen forms. The chemiluminescence amplitude was shown to increase with adhesion of thymocytes exposed to 1-5 Gy radiation and to decrease after a dose of 10 Gy. In cells of bursa of Fabricius, the analogous response to activation or irradiation was not observed.

Effect of exposure to operant-controlled microwaves on certain blood and immunological parameters in the young chick.

Twenty-two 1-wk-old broiler chicks (Gallus domesticus) were housed at 16 C and operantly conditioned to activate either a 250-W infrared bulb (control) or a microwave generator delivering 13 mW/cm2 (treated). Plasma corticosterone concentration did not differ between groups (P greater than .05) at 4 wk of age. At that time the birds were killed, and post-mortem examination revealed no treatment differences in gross morphology of the chicks or in weights of spleen and bursa of Fabricius (P greater than .05). Histological study of comparable segments of spleen, bursa, adrenal, and thyroid tissue did not show differences in any of the chosen parameters (P greater than .05). Heterophil:lymphocyte ratios, packed cell volume, and total plasma protein content were similar between groups (P greater than .05). These results suggest that operant exposure to low density microwave radiation did not result in stress or immunological disturbances.

Cyclic nucleotides in chicken peripheral blood lymphocytes.

The influence of irradiation or surgical removal of one of two central lymphatic organs (thymus, bursa) on cAMP and cGMP intracellular concentration in chicken lymphocytes was studied. Results revealed drastic changes mainly in cAMP concentration in thymectomized or bursectomized chickens. Possible consequences of the above changes on the maturation, differentiation and proliferation of lymphocytes were discussed.

Defective bursa regeneration after irradiation of young thymectomized chickens.

The ability of the bursa of Fabricius to regenerate after gamma-irradiation and bone marrow reconstitution was examined in chickens thymectomized (TX) immediately after hatching. Irradiation (2 X 500 R) 3 weeks after hatching was followed by impaired bursa regeneration, as judged both by bursa/body weight ratios and by bursa follicle development 3-6 weeks later in TX as compared to control birds. Germinal center formation in the spleen was deficient, and immune responses to sheep erythrocytes (SRBC) and B. abortus (BA) were moderately reduced in the TX as compared to control birds irradiated at 3 weeks but not in TX birds irradiated at 5 weeks of age.

[Analysis of cellular components in immunocompetent organs treated with ionizing radiations]. / Analisi dei componenti cellulari degli organi immunocompetenti sottoposti a radiazioni ionizzanti.

The nucleic acid and protein content has been evaluated in lymphoid cells from the thymus and the Bursa of Fabricius of chicks exposed to different doses of radiation. A different response to radiation damage of the two cell populations is suggested by these analysis when compared with ultrastructural data.

[Effects of ionizing radiations on the ultrastructure of bursa of Fabricius]. / Effetti delle radiazioni ionizzanti sulla ultrastruttura della borsa di Fabrizio.

The alterations induced in the lymphoid and epitelial cells of the Bursa of Fabricius in chicks exposed at different doses of gamma rays mainly occur during the interfase. The extent of these alterations appears reduced in comparison with that observed in the chick thymus treated in the same way.

Experimentally induced synovitis of chickens with Mycoplasma synoviae: effects of bursectomy and thymectomy on course of the infection for the first four weeks.

Specific pathogen-free chickens (bursectomized and x-irradiated (SBx-X), thymectomized and x-irradiated, x-irradiated, as well as nontreated) were inoculated (in the right tibiometatarsal joint) at the 4th week after hatching with a synovitis-derived Mycoplasma synoviae strain. Differences were not observed in recovery rate of mycoplasmas from tissues among these groups. The SBx-X chickens which were killed at 2 and 4 weeks after the intraarticular inoculation or which died during this period and bacteremia and severe synovitis with edema and heterophil infiltration in synovial fluid and in area from synovial membrane to subcutaneous tissue. Swelling of left leg joints or foot pads were observed mainly in the SBx-X group. A significant difference in the mortality rate and severity of airsacculitis was observed between SBx-X and other groups. The thymectomized and x-irradiated chickens did not show edema, synovial fluid, or swelling in the joint area. However, small lymph follicles composed of lymphoid and plasma cell were formed locally in synovial membranes of various joints. These results indicated that bursa-dependent lymphocytes are correlated with resistance to develop the lesions and that thymus-dependent lymphocytes are necessary for macroscopic lesions to develop.

Bursa of Fabricus: uptake of radioactive particles and radiotoxic "sealing" of bursal follicles.

Making use of the fact that the avian bursa is uniquely equiped for uptake, degradation and storage of particulate matter from the cloacal lumen, we administered 239Pu(IV) perorally or via the cloaca to cause radiotoxic damage to the bursal tissue. This resulted in a involution of the follicles, reduction of the lymphocyte mass, predominance of smaller lymphoid cells in the medulla as compared to controls, disappearance of tuft epithelia, formation of a sub-epithelial fibrous layer in many follicles and impairment or an almost complete loss of the capacity of the bursa to take up particulate matter. Concomitant with these changes was a reduction in the concentration of serum IgG. These findings are discussed in relation to the immunologic contact role of the bursa.

Micro-radioimmunoassay for antibodies to Newcastle disease virus in the chicken.

An indirect micro-radioimmunoassay is described in which chicken anti-Newcastle disease virus antibody was detected, with radioactively labeled rabbit anti-chicken Fab, on virus-infected microcultures of chick embryo fibroblasts. Newcastle disease virus-infected microcultures were formalin fixed and stored at 4 degrees C for up to 4 months without affecting the sensitivity of the test. The micro-technique was found to be highly sensitive and specific assay of anti-viral antibody and may allow detection of immunoglobulin class of anti-Newcastle disease virus antibody.