OBJECTIVETo investigate the effects of microwave radiation on thymocytes in mice at different power densities.

METHODSThe experimental animals were whole-body exposed to microwave radiation with frequency of 2,450 MHz, power density of 1, 5, 15 mW/cm(2) respectively 1 h everyday for 30 days. Then the thymus were taken out after the mice were decapitated. Thymus index, morphological characteristics of thymus were examined. The changes of thymus T-cell subgroups, cell cycle progression in thymocytes and cellular apoptosis were detected with flow cytometry (FCM).

RESULTSThe body weights of animals in 5, 15 mW/cm(2) irradiation groups [(28.10 +/- 1.46), (27.50 +/- 2.52) g] were lower than that of the control [(31.95 +/- 2.51) g] (P < 0.05). Pathological observation showed dark red piece of nucleus, some nuclei inclined to one side, slight increase in hassall body. The expressions of CD8 in 5, 15 mW/cm(2) irradiation groups (29.14% +/- 1.68%, 29.18% +/- 0.81%) were higher than that in control group (26.95% +/- 1.27%) (P < 0.05). The percentages of G(2) + M phase thymocytes in both radiation groups (12.24% +/- 1.82%, 11.19% +/- 1.36%) were lower than that in control group (14.58% +/- 0.64%) (P < 0.01). Thymocytic apoptosis rates in the three experimental groups (7.18% +/- 0.99%, 10.06% +/- 1.58%, 9.45% +/- 0.92%) were higher than that in control (4.25% +/- 1.63%) (P < 0.01), but the evident difference between 5 mW/cm(2) and 15 mW/cm(2) was not found (P > 0.05).

CONCLUSIONSub-chronic microwave exposure (2 450 MHz, 5, 15 mW/cm(2)) could induce thymocyte apoptosis, cause pathological changes in thymus, and affect cell cycle progression, thus may inhibit the immune function of the animal.

Animals ; Apoptosis ; radiation effects ; Dose-Response Relationship, Radiation ; Female ; Male ; Mice ; Microwaves ; adverse effects ; T-Lymphocytes ; radiation effects ; Thymus Gland ; cytology ; radiation effects

Adopting the cell model of multilayer spherical symmetry and the circuit analysis, the present paper gives the calculated results of the voltages on each of several parts of malignant Tonsillar B-cells and Jurkat T lymphocytes when the first-order Gaussian pulses at different central frequency apposed on them. The relationship between the central frequency and the transmembrane voltages of plasma membrane is also given. The optimum frequency causing electroporation in nuclear envelope is given as well. The paper discusses the reasons of electroporation in membrane and DNA degradation in nuclear. The work provides a reference for usage of transient bipolar electric pulses in cancer treatment.
Apoptosis ; radiation effects ; B-Lymphocytes ; cytology ; radiation effects ; Cell Line, Tumor ; Cell Membrane ; physiology ; Electromagnetic Fields ; Electroporation ; methods ; Humans ; Jurkat Cells ; Nuclear Envelope ; pathology ; radiation effects

Nuclear envelope voltages of T cells were analyzed with a lumped circuitry for cells in combination with frequency domain power density of Gaussian pulses and monocycle pulses. According to the differences in geometric and electric parameters between normal and malignant T cells, circuitry analysis was performed. Theoretical evaluations indicated that apoptosis of malignant T cells was of feasibility, which could be applied in cancer therapy. The evaluations were in accord with the published experimental findings.
Animals ; Apoptosis ; radiation effects ; Electric Stimulation ; Electromagnetic Fields ; Electrophysiology ; Fourier Analysis ; Humans ; Jurkat Cells ; Nuclear Envelope ; pathology ; radiation effects ; T-Lymphocytes ; cytology ; radiation effects

OBJECTIVETo establish a method for inducing apoptosis of rhesus peripheral blood lymphocytes (PBLs).

METHODSRhesus PBLs were irradiated with X-ray, (60)Co gamma-rays and ultraviolet (UVC254 nm), respectively, and the cell apoptosis was evaluated with flow cytometry using annexin-V staining and propidium iodide staining.

RESULTSX-ray and (60)Co gamma-ray irradiation induced only low apoptotic rates of the PBLs, and UVC resulted in the highest apoptotic rate of about 60%. UVC irradiation of the PBLs in RPMI supplemented with 10% heat-inactivated fetal calf serum for 60 min at a distance of 20 cm led to an early apoptotic rate of 58.85% and necrotic rate of 11.5%. The apoptotic rate of PBLs increased in a dose- and time-dependent fashion.

CONCLUSIONFor inducing apoptosis of the rhesus PBLs, UVC can be more effective than X-ray and (60)Co gamma-ray. The highest apoptotic rate can be achieved when the rhesus PBLs in RPMI supplemented with 10% heat-inactivated fetal calf serum are exposed to UVC for 60 min at the distance of 20 cm.

Animals ; Apoptosis ; radiation effects ; Cells, Cultured ; Dose-Response Relationship, Radiation ; Flow Cytometry ; Gamma Rays ; Leukocytes, Mononuclear ; cytology ; radiation effects ; Lymphocytes ; cytology ; radiation effects ; Macaca mulatta ; Male ; Time Factors ; Ultraviolet Rays ; X-Rays

AIM: Radiation induces an important apoptosis response in irradiated organs. The objective of this study was to investigate the radioprotective effect of tetramethylpyrazine (TMP) on irradiated lymphocytes and discover the possible mechanism of protection. METHOD: Lymphocytes were pretreated for 12 h with TMP (25-200 μmol·L(-1)) and then exposed to 4 Gy radiation. Cell apoptosis and the signaling pathway were analyzed. RESULTS: Irradiation increased cell death, DNA fragmentation, activated caspase activation and cytochrome c translocation, downregulated B-cell lymphoma 2 (Bcl-2) and up-regulated Bcl-2-associated X protein (Bax). Pretreated with TMP significantly reversed this tendency. Several anti-apoptotic characteristics of TMP, including the ability to increase cell viability, inhibit caspase-9 activation, and upregulate Bcl-2 and down-regulate Bax in 4Gy-irradiated lymphocytes were determined. Signal pathway analysis showed TMP could translate nuclear factor-κB (NF-κB) from cytosol into the nucleus. CONCLUSION The results suggest that TMP had a radioprotective effect through the NF-κB pathway to inhibit apoptosis, and it may be an effective candidate for treating radiation diseases associated with cell apoptosis.
Apoptosis ; drug effects ; radiation effects ; Cell Line ; Cell Survival ; drug effects ; radiation effects ; DNA Fragmentation ; drug effects ; radiation effects ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Lymphocytes ; cytology ; drug effects ; radiation effects ; NF-kappa B ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Pyrazines ; pharmacology ; Radiation-Protective Agents ; pharmacology ; bcl-2-Associated X Protein ; genetics ; metabolism

Cytogenetic and hematological analyses were performed on the peripheral blood lymphocytes (PBLs) obtained from Korean native cattle bred in the vicinity of three nuclear power plants (Wolsong, Uljin and Yeonggwang) and in a control area. The micronucleus (MN) rates for the cattle from the Wolsong, Uljin and Yeonggwang nuclear power plants and for the control area were 9.87 +/- 2.64, 8.90 +/- 3.84, 9.20 +/- 3.68 and 9.60 +/- 3.91 per 1,000 cytokinesis-blocked lymphocytes, respectively. The apparent difference is not statistically significant. The MN frequencies of PBLs from cattle bred in the four areas are within the background variation for this study. The MN frequencies and hematological values were similar regardless of whether the cattle were bred near a nuclear power plant or in the control area.
Animals ; Blood Cell Count/veterinary ; Cattle/*blood ; Cytokinesis ; Hematocrit/veterinary ; Hemoglobins/analysis ; Lymphocytes/cytology/*radiation effects ; Micronucleus Tests/*veterinary ; *Power Plants ; Radioactive Pollutants/pharmacology

In order to determine the effect of ultraviolet radiation (UVR) on the cell adhesion molecules expressed in human dermal microvascular endothelial cells (HDMEC), the cells were exposed to varying UVR doses and the cell surface was examined for expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM- 1), and E-selectin. The effect of UVB irradiation on the binding of T lymphocytes to HDMEC was also examined. UVA irradiation did not affect the surface expression of ICAM-1, VCAM-1, or E-selectin on the HDMEC. However, following UVB exposure, ELISA demonstrated a significant increase in the baseline ICAM-1 cell surface expression on the HDMEC. However, no induction of either E-selectin or VCAM-1 was noted. UVB also significantly augmented ICAM-1 induction by IL-1 alpha and TNF- alpha. VCAM-1 was induced by stimulating HDMEC with IL-1alpha following a UVB irradiation dose of 100 mJ/cm2. Flow cytometric analysis of the HDMEC stimulated with IL-1 alpha for 24h demonstrated that 12% of the cells expressed VCAM-1 but either IL-1 alpha or UVB irradiation alone failed to induce VCAM-1 expression. Enhancement of T cell-HDMEC binding by IL-1 alpha; or TNF- alpha treatment was not significantly affected after UVB irradiation. This study demonstrated that UVB irradiation can alter ICAM-1 and VCAM-1 expression on the HDMEC surface and that augmentation of ICAM-1 expression and the IL-1 alpha -dependent induction of VCAM-1 following UVB exposure might be important steps in the pathogenesis of sunburn.
Cell Adhesion/radiation effects ; Cell Adhesion Molecules/*metabolism ; Cells, Cultured ; Endothelium, Vascular/cytology/*physiology ; Human ; Microcirculation ; Skin/*blood supply ; T-Lymphocytes/*physiology ; *Ultraviolet Rays

Constructing a bone marrow chimera prior to graft transplantation can induce donor-specific immune tolerance. Mixed chimerism containing hematopoietic cells of both recipient- and donor-origin has advantages attributed from low dose of total body irradiation. In this study, we explored the mechanism of mixed chimerism supplemented with depletion of Natural Killer cells. Mixed chimerism with C57BL/6 bone marrow cells was induced in recipient BALB/c mice which were given 450 cGy of gamma-ray irradiation (n = 16). As revealed by reduced proliferation and cytokine production in mixed leukocyte reaction and ELISpot assay (24.6 vs 265.5), the allo-immune response to bone marrow donor was reduced. Furthermore, the induction of transferable immunological tolerance was confirmed by adoptive transfer and subsequent acceptance of C57BL/6 skin graft (n = 4). CD4+FoxP3+ regulatory T cells were increased in the recipient compartment of the mixed chimera (19.2% --> 33.8%). This suggests that regulatory T cells may be therapeutically used for the induction of graft-specific tolerance by mixed chimerism.
Animals ; Bone Marrow Cells/cytology ; *Bone Marrow Transplantation ; Cell Proliferation ; Chimerism ; Cytokines/metabolism ; Gamma Rays ; Graft Survival ; *Immune Tolerance ; Killer Cells, Natural/immunology/radiation effects ; Leukocytes/immunology/radiation effects ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Models, Animal ; Skin Transplantation ; T-Lymphocytes, Regulatory/cytology/*immunology/metabolism ; Whole-Body Irradiation

OBJECTIVETo study the effect of pretreatment with apoptotic donor spleen cells on spleen lymphocyte function of recipient rats undergoing islet transplantation to explore new approaches to prolong islet graft survival.

METHODSApoptotic spleen cells from donor rats were obtained by exposure to γ-ray irradiation from (60)Co. Diabetic SD rat models were randomly divided into 4 groups to receive tail vein injections with saline (group A), normal cells (group B), apoptotic donor cells (group C), or necrotic donor cells (group D). One week later, orthotopic transplantation of islets under the renal capsule was performed. Before and at 1 and 2 weeks after islet transplantation, the recipient rats were examined for proliferative activity of spleen lymphocytes with CFSE cell staining and for IL-2 and IL-10 expressions in the cells using ELISA.

RESULTSPretreatment with donor apoptotic cells significantly suppressed the proliferative activity of recipient spleen lymphocytes before and at 1 and 2 weeks after islet transplantation as compared with the other three groups (P<0.05). The level of IL-2 was significantly decreased while IL-10 increased in apoptotic donor cell pretreatment group compared with those in the other 3 groups at each time point of observation.

CONCLUSIONThe effect of pretreatment with apoptotic donor cells on recipient spleen lymphocytes suggest an important role of apoptotic donor spleen cells in immune tolerance of grafts.

Animals ; Apoptosis ; immunology ; Cell Proliferation ; Cobalt Radioisotopes ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; surgery ; Gamma Rays ; Graft Survival ; Immune Tolerance ; Interleukin-10 ; metabolism ; Interleukin-2 ; metabolism ; Islets of Langerhans Transplantation ; Lymphocyte Transfusion ; Lymphocytes ; metabolism ; pathology ; radiation effects ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Spleen ; cytology ; metabolism ; radiation effects

To determine whether gamma irradiation influences phenotype and function of human dendritic cells (DC) in vitro, dendritic cells were induced from the peripheral blood mononuclear cells of multiple sclerosis patients with RPMI 1640 medium containing recombinant human GM-CSF (rhGM-CSF, 800 U/ml) and recombinant human IL-4 (rhIL-4, 500 U/ml). Phenotypic changes were monitored by light microscopy. Lipopolysaccharide at a concentration of 5 micro g/ml was added into the cultures after 6 days of growth for DC complete maturation, and the cells were cultured for another 24 hours. The harvested DC on day 7 were divided equally into several parts. One part was used as non-irradiated DC (naive DC) while the other parts were irradiated by gamma ray at a dose of 25 Gy and 30 Gy respectively. Cell surface molecules were analyzed by flow cytometry. The capability of DC to stimulated autologous T cell proliferation were determined. The results showed that gamma irradiation reduced expression of CD86, CD80 and HLA-DR molecules on dendritic cells, especially CD86 molecules. Dendritic cells effectively stimulated autologous T cells proliferation while irradiated DC in all groups showed profound decrease of capability to promote T cells proliferation. It is concluded that gamma irradiation of dendritic cells not only influenced phenotype of DC but also altered their function as stimulator cells in mixed lymphocyte reaction.
Antigens, CD ; analysis ; B7-1 Antigen ; analysis ; B7-2 Antigen ; Cell Division ; immunology ; Dendritic Cells ; drug effects ; immunology ; radiation effects ; Flow Cytometry ; Gamma Rays ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; HLA-DR Antigens ; analysis ; Humans ; Immunophenotyping ; Interleukin-4 ; pharmacology ; Membrane Glycoproteins ; analysis ; Multiple Sclerosis ; blood ; Recombinant Proteins ; pharmacology ; T-Lymphocytes ; cytology ; immunology