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1.
The radioprotective activity of extracts from the red seaweed Callophyllis (C.) japonica was investigated in mice that underwent whole-body exposure to gamma radiation. A methanol extract of C. japonica and its fractions [hexane, ethyl acetate (EtOAc), butanol and the remaining H2O] were used. Each fraction (100 mg/kg body weight) was administered intraperitoneally (i.p.) 2 times into the BALB/c mice, once at 1 and once at 24 h before exposure to 9 Gray (Gy) of gamma radiation. Pre-irradiation administration of the hexane and EtOAc fractions saved the mice, with their survival rates being greater than 80% at 30 days post-irradiation; the mice that were pretreated with the other fractions showed survival rates lower than 20% over the same time period. To examine the effect of each C. japonica fraction on the survival of intestinal and bone marrow stem cells, the number of intestinal crypts and bone marrow cells in the gamma-irradiated mice were examined. Pre-treatment of mice (i.p., 100 mg/kg body weight at 1 and 24 h before irradiation) with the hexane or EtOAc fraction prior to 6-Gy irradiation significantly protected the number of jejunal crypts and bone marrow cells at 9 days after irradiation. These findings suggest that certain extracts from C. japonica, when they are administered prior to irradiation, play an important role in the survival of irradiated mice, and this is possibly due to the extracts protecting the hematopoietic cells and intestinal stem cells against gamma irradiation.  相似文献   

2.
A normal prion protein (PrPc) is converted to a protease-resistant isoform by an apparent self-propagating activity in transmissible spongiform encephalopathy, a neurodegenerative disease. The cDNA encoding open reading frame (ORF) of the bovine prion protein gene (Prnp) was cloned from Korean cattle by PCR, and was transfected into Chinese hamster ovary (CHO-K1) cells using lipofectamine. The gene expression of the cloned cDNA was confirmed by RT-PCR and Western blotting with the monoclonal antibody, 6H4. Cellular changes in the transfected CHO-K1 cells were investigated using parameters such as MTT, lactate dehydrogenase (LDH), and superoxide dismutase (SOD) activities, as well as nitric oxide (NO) production, and an apoptosis assay. In the MTT and LDH assays, the bovine PrnP-transfectant showed a lower proliferation rate than the wild-type (p < 0.05). Production of NO, after LPS or ConA stimulation, was not detected in either transfectants or CHO-K1 cells. In SOD assay under ConA stimulation, the SOD activity of transfectants was 10 times higher than that of CHO-K1 cells at 6 h after treatment (p < 0.05). The genomic DNA of both the transfectants and control cells began to be fragmented at 6 h after treatment with cyclohexamide. Caspase-3 activity was reduced by transfection with the bovine Prnp (p < 0.05). Conclusively, the viability of transfectants expressing exogenous bovine Prnp was decreased while the capacities for cellular protection against antioxidative stress and apoptosis were increased.  相似文献   

3.
Fucoidan is a sulfated polysaccharide purified from brown algae including Fucus vesiculosus and has a variety of biological effects including mobilization of hematopoietic progenitor cells. Recently, we demonstrated that fucoidan stimulates the antigen-presenting functions of dendritic cells. In this study, we investigated the radioprotective effects of fucoidan on bone marrow cells (BMCs), which are the main cellular reservoir for the hematopoietic and immune system. To evaluate the effects of fucoidan, we assayed cell viability and immune responses. In a viability assay, fucoidan significantly increased the viability of BMCs. Based on the results of flow cytometric analysis, the increased viability of fucoidan-treated BMCs was attributed to the inhibition of radiation-induced apoptosis. Furthermore, fucoidan altered the production of immune-related cytokines from BMCs and increased the capability of BMCs to induce proliferation of allogeneic splenocytes. Taken together, our study demonstrated that fucoidan has radioprotective effects on BMCs with respect to cell viability and immunoreactivity. These results may provide valuable information, useful in the field of radiotherapy.  相似文献   

4.
This study was to investigate the anti-obesity effects of diglyceride (DG)-conjugated linoleic acid (CLA) containing 22% CLA as fatty acids in C57BL/6J ob/ob male mice. There were four experimental groups including vehicle control, DG, CLA, and DG-CLA. The test solutions of 750 mg/kg dose were orally administered to the mice everyday for 5 weeks. CLA treatments significantly decreased mean body weight in the obese mice throughout the experimental period compared to the control (p < 0.01). All test solutions significantly decreased the levels of triglyceride, glucose and free fatty acids in the serum compared with control (p < 0.05). The levels of total cholesterol were also significantly reduced in DG and DG-CLA groups compared with the control group (p < 0.05). CLA significantly decreased weights of renal and epididymal fats compared with the control (p < 0.05). DG and DG-CLA also significantly decreased the epididymal fat weights compared with the control (p < 0.05). A remarkable decrease in the number of lipid droplets and fat globules was observed in the livers of mice treated with DG, CLA, and DG-CLA compared to control. Treatments of DG and CLA actually increased the expression of peroxisome proliferator-activated receptor gamma. These results suggest that DG-CLA containing 22% CLA have a respectable anti-obesity effect by controlling serum lipids and fat metabolism.  相似文献   

5.
Recent studies using several Babesia spp. have demonstrated that these species commonly recognize host sialic acids of red blood cells (RBCs) for their invasion. Glycophorin A (GPA), which is a major carrier of the sialic acids on RBCs, is a possible invasive receptor for Babesia parasites. In the present study, a variant of Babesia rodhaini was successfully isolated from a GPA homozygous knockout (GPA−/−) mouse infected with an Australian strain of B. rodhaini which had originally been unable to replicate in GPA−/− mice. The isolated parasite (designated as an OB1 variant) caused lethal infection to wild-type mice, as in the case of the parent Australian strain. However, although the growth of the OB1 variant in GPA−/− mice was comparable with that in wild-type mice at 1–4 days after infection, the growth was significantly inhibited from day 5 onward, leading to the eventual survival of the GPA−/− mice. Resistance of GPA−/− mice against OB1 infection was lost by splenectomy, although the cytokine responses to the infection in the sera of GPA−/− mice were similar to those of wild-type mice. The autoantibody levels to GPA-defective RBCs in the sera of GPA−/− mice were depressed at a lower level at 0–2 days after infection than those of wild-type mice, while the levels of GPA−/− mice progressively increased and reached comparable levels to those of wild-type mice at day 3 or later. These results indicate that the isolated OB1 variant has a GPA-independent invasion pathway into murine RBCs and suggest that the resistance of GPA−/− mice against infection with the OB1 variant may be attributed to the effective clearance of the parasitized RBCs lacking GPA in the spleen, possibly mediated by preferential autoantibody binding to the RBC membrane.  相似文献   

6.
Media-based bacteriological testing will fail to detect non-culturable organisms and the risk of consuming viable but non-culturable (VBNC) Listeria monocytogenes is unknown. We have here studied whether L. monocytogenes obtained from seafoods, processing environment and clinical cases enter the VBNC state and assessed the virulence of the non-culturable forms of the bacteria. A number of 16 L. monocytogenes strains were starved in microcosm water at 4 °C until loss of culturability. Metabolic activity in the VBNC form was measured as ATP generation using a luciferase assay and membrane integrity was examined using the LIVE/DEAD BacLight assay. All tested L. monocytogenes strains entered the VBNC state after starvation in microcosm water. Ongoing mRNA synthesis of hly in VBNC L. monocytogenes cells re-incubated in culture medium indicated a potential virulence of these forms. Sodium pyruvate and replenishment of nutrient were used in attempts to resuscitate VBNC cells. However, VBNC L. monocytogenes were not resuscitated under these conditions. VBNC L. monocytogenes were tested for virulence in a cell plaque assay and by intraperitoneally inoculation in immunodeficient RAG1−/− mice. Inoculation of VBNC L. monocytogenes in immunodeficient mice did not cause morbidity, and plaque assay on HT-29 cells in culture indicated that the VBNC cells were avirulent. The results indicate that the risk of non-culturable L. monocytogenes in foods, when the VBNC state is induced by starvation, is negligible.  相似文献   

7.
The aim of this study was to evaluate the immune responses to intranasal and intrapulmonary vaccinations with the attenuated Mycoplasma hyopneumoniae (Mhp) 168 strain in the local respiratory tract in pigs. Twenty-four pigs were randomly divided into 4 groups: an intranasal immunization group, an intrapulmonary immunization group, an intramuscular immunization group and a control group. The levels of local respiratory tract cellular and humoral immune responses were investigated. The levels of interleukin (IL)-6 in the early stage of immunization (P<0.01), local specific secretory IgA (sIgA) in nasal swab samples (P<0.01); and IgA- and IgG-secreting cells in the nasal mucosa and trachea were higher after intranasal vaccination (P<0.01) than in the control group. Interestingly, intrapulmonary immunization induced much stronger immune responses than intranasal immunization. Intrapulmonary immunization also significantly increased the secretion of IL-6 and local specific sIgA and the numbers of IgA- and IgG-secreting cells. The levels of IL-10 and interferon-γ in the nasal swab samples and the numbers of CD4+ and CD8+ T lymphocytes in the lung and hilar lymph nodes were significantly increased by intrapulmonary immunization compared with those in the control group (P<0.01). These data suggest that intrapulmonary immunization with attenuated Mhp is effective in evoking local cellular and humoral immune responses in the respiratory tract. Intrapulmonary immunization with Mhp may be a promising route for defense against Mhp in pigs.  相似文献   

8.
We previously induced protective immune response by oral immunization with yeast expressing the ApxIIA antigen. The ApxI antigen is also an important factor in the protection against Actinobacillus pleuropneumoniae serotype 5 infection; therefore, the protective immunity in mice following oral immunization with Saccharomyces cerevisiae expressing either ApxIA (group C) or ApxIIA (group D) alone or both (group E) was compared with that in two control groups (group A and B). The immunogenicity of the rApxIA antigen derived from the yeast was confirmed by a high survival rate and an ApxIA-specific IgG antibody response (p < 0.01). The highest systemic (IgG) and local (IgA) humoral immune responses to ApxIA and ApxIIA were detected in group E after the third immunization (p < 0.05). The levels of IL-1β and IL-6 after challenge with an A. pleuropneumoniae field isolate did not change significantly in the vaccinated groups. The level of TNF-α increased in a time-dependent manner in group E but was not significantly different after the challenge. After the challenge, the mice in group E had a significantly lower infectious burden and a higher level of protection than the mice in the other groups (p < 0.05). The survival rate in each group was closely correlated to the immune response and histopathological observations in the lung following the challenge. These results suggested that immunity to the ApxIA antigen is required for optimal protection.  相似文献   

9.
Neospora caninum is an intracellular parasite that causes major economic impact on cattle raising farms, and infects a wide range of warm-blooded hosts worldwide. Innate immune mechanisms that lead to protection against this parasite are still unknown. In order to investigate whether myeloid differentiation factor 88 (MyD88) is required for resistance against N. caninum, genetically deficient mice (MyD88−/−) and wild type littermates were infected with live tachyzoites and the resistance to infection was evaluated. We found that sub-lethal tachyzoite doses induced acute mortality of MyD88−/− mice, which succumbed to infection due to uncontrolled parasite replication. Higher parasitism in MyD88−/− mice was associated with the lack of IL-12 production by dendritic cells, delayed IFN-γ responses by NKT, CD4+ and CD8+ T lymphocytes, and production of high levels of IL-10. MyD88−/− mice replenished with IL-12 and IFN-γ abolished susceptibility as the animals survived throughout the experimental period. We conclude that protective IFN-γ-mediated immunity to N. caninum is dependent on initial MyD88 signaling, in a mechanism triggered by production of IL-12 by dendritic cells. Further knowledge on Toll-like receptor recognition of N. caninum antigens is encouraged, since it could generate new prophylactic and therapeutic tools to control parasite burden.  相似文献   

10.
We investigated the effect of the Y chromosome on testis weight in (B6.Cg-Ay × Y-consomic mouse strain) F1 male mice. We obtained the following results: (1) Mice with the Mus musculus domesticus-type Y chromosome had significantly heavier testis than those with the M. m. musculus-type Y chromosome. (2) Variations in Usp9y and the number of CAG repeats in Sry were significantly associated with testes weight. The Ay allele was correlated with a reduced testis weight, and the extent of this reduction was significantly associated with a CAG repeat number polymorphism in Sry. These results suggest that Y chromosome genes not only influence testis weight but also modify the effect of the Ay allele in mediating this phenomenon.  相似文献   

11.
The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.  相似文献   

12.
Although ionizing radiation is known to induce cellular senescence in vitro and in vivo, its long-term in vivo effects are not well defined. In this study, we examined the prolonged expression of senescence markers in mice irradiated with single or fractionated doses. C57BL/6 female mice were exposed to 5 Gy of γ-rays in single or 5, 10, 25 fractions. At 2, 4, and 6 months after irradiation, senescence markers including mitochondrial DNA (mtDNA) common deletion, p21, and senescence-associated β-galactosidase (SA β-gal) were monitored in the lung, liver, and kidney. Increases of mtDNA deletion were detected in the lung, liver, and kidney of irradiated groups. p21 expression and SA β-gal staining were also increased in the irradiated groups compared to the non-irradiated control group. Increases of senescence markers persisted up to 6 months after irradiation. Additionally, the extent of mtDNA deletion and the numbers of SA β-gal positive cells were greater as the number of radiation fractions increased. In conclusion, our results showed that ionizing radiation, especially that delivered in fractions, can cause the persistent upregulation of senescence marker expression in vivo. This should be considered when dealing with chronic normal tissue injuries caused by radiation therapy or radiation accidents.  相似文献   

13.
Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group.  相似文献   

14.
Bovine babesiosis is a livestock disease known to cause economic losses in endemic areas. The apicomplexan parasite Babesia bovis is able to invade and destroy the host’s erythrocytes leading to the serious pathologies of the disease, such as anemia and hemoglobinuria. Understanding the egress mechanisms of this parasite is therefore a key step to develop new therapeutic strategies. In this study, the possible involvement of Ca2+ in the egress of B. bovis merozoites from infected erythrocytes was investigated. Egress was artificially induced in vitro using calcium ionophore A23187 and thapsigargin to increase Ca2+ concentration in the cytosol of the parasite cells. The increased intracellular Ca2+ concentration following these treatments was confirmed using live cell Ca2+ imaging with confocal laser scanning microscopy. Based on our findings, we suggest a Ca2+ signalling pathway in the egress of B. bovis merozoites.  相似文献   

15.
In this study, specific sequences within three genes (3D, VP4 and 2B) of the foot-and-mouth disease virus (FMDV) genome were determined to be effective RNAi targets. These sequences are highly conserved among different serotype viruses based on sequence analysis. Small interfering RNA (siRNA)-expressing plasmids (p3D-NT19, p3D-NT56, pVP4-NT19, pVP4-NT65 and p2B-NT25) were constructed to express siRNA targeting 3D, VP4 and 2B, respectively. The antiviral potential of these siRNA for various FMDV isolates was investigated in baby hamster kidney (BHK-21) cells and suckling mice. The results show that these siRNA inhibited virus yield 10- to 300-fold for different FMDV isolates of serotype O and serotype Asia I at 48 h post infection in BHK-21 cells compared to control cells. In suckling mice, p3D-NT56 and p2B-NT25 delayed the death of mice. Twenty percent to 40% of the animals that received a single siRNA dose survived 5 days post infection with serotype O or serotype Asia I. We used an attenuated Salmonella choleraesuis (C500) vaccine strain, to carry the plasmid that expresses siRNA directed against the polymerase gene 3D (p3D-NT56) of FMDV. We used guinea pigs to evaluate the inhibitory effects of recombinant S. cho (p3D-NT56/S. cho) on FMDV infection. The results show that 80% of guinea pigs inoculated with 109 CFU of p3D-NT56/S. cho and challenged 36 h later with 50 ID50 of homologous FMDV were protected. We also measured the antiviral activity of p3D-NT56/S. cho in swine. The results indicate that 100% of the animals treated with 5 × 109 CFU of p3D-NT56/S. cho were protected in 9 days.  相似文献   

16.
Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 107 C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.  相似文献   

17.
We investigated the immune response induced by the Francisella (F.) tularensis live vaccine strain (LVS) and the Pohang isolate. After the Balb/c mice were infected intradermally (i.d) with 2 × 104 cfu of F. tularensis LVS and Pohang, respectively, their blood and organs were collected at different times; 0, 3, 6, 24, 72, 96, 120 and 168 h after infection. Using these samples, RT-PCR and ELISA analysis were carried out for the comparative study of the cytokines, including TNF-α, INF-γ, IL-2, IL-4, IL-10 and IL-12. In the Pohang-infected mice at 120 h, the liver showed a 53 times higher level of TNF-α and a 42 times higher level of IFN-γ than the respective levels at the early time points after infection. The levels of TNF-α and IFN-γ induced by LVS were 5 times lower than those induced by the Pohang isolate. Also, the organs from the Pohang-infected mice showed higher levels of TNF-α, IFN-γ, IL-10 and IL-12 than the levels in the LVS-infected mice. The blood from the Pohang-infected mice at 120 h revealed about a 40 times increased level of IFN-γ, and IL-10 was also increased by 4 times at 96 h compared to an early infection time point, while IL-4 was not induced during the whole infection period. These results suggest that F. tularensis may induce a Th1-mediated immune response to in vivo infection and the Pohang isolate has a higher capacity than the LVS to induce an acute immune response in Blab/c mice.  相似文献   

18.
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19.
Alterations of genes are known to be critical for the induction of tumorigenesis, but the mechanism of ovarian carcinogenesis is little understood and remains to be elucidated. In this study, we investigated the roles of brca1, brca2 and p53 genes in the development of ovarian cancer using conditional knockout mice generated by a Cre-loxP recombinant system. Following the application of recombinant adenovirus expressing Cre in vitro, the proliferation of ovarian surface epithelium (OSE) was increased. For instance, a significant increase in cell growth was observed in OSE cells in vitro by conditional knockout isolated from the mice bearing concurrent floxed copies of brca1 and brca2/p53. However, the proliferative effect of the ovarian cells was not observed in concurrent brca1/brca2 or p53 knockout mice in vivo, indicating that we could not observe the direct evidence of the involvement of brca1, brca2, and p53 in ovarian carcinogenesis. Since morphological changes including tumor formation were not observed in mice bearing floxed copies of concurrent brca1/brca2 or p53, the inactivation of brca1/2 or p53 is not sufficient for the induction of tumor formation. Taken together, these results suggest that the deficiency of these genes may not be involved directly in the mechanism of ovarian carcinogenesis.  相似文献   

20.
We previously demonstrated that stimulation of bovine peripheral blood mononuclear cells (PBMCs) with staphylococcal enterotoxin C (SEC), led to an inversion of the CD4+:CD8+ T cell ratio and generation of an atypical CD8+ T cell subpopulation expressing CD26. In the present study, we examined T cell apoptosis and proliferation profiles of PBMC subpopulations in cultures stimulated with SEC. Unlike when stimulated with concanavalin A, nucleic acid synthesis in bovine PBMC cultures stimulated with SEC was low during the first four days but increased greatly on day 5. In contrast, nucleic acid synthesis in human PBMC cultures stimulated with SEC increased continuously. To investigate the mechanism of delayed bovine T cell proliferation, various cell phenotypes were monitored. The inversion of the bovine CD4+:CD8+ T cell ratio in PBMC cultures stimulated by SEC was associated with higher proliferation and lower apoptosis of CD8+ T cells compared to CD4+ T cells. The mRNA levels for interleukin (IL)-4 and IL-13 were sustained over 4 days but IL-12 mRNA levels dropped to background on day 2. These data suggest that SEC induces a prolonged Th-2-biased microenvironment, and together with the inversion of the bovine CD4+:CD8+ T cell ratios in bovine PBMC cultures with SEC, may in part explain the inability of the mammary immune system to establish an effective response to Staphylococcus aureus infections.  相似文献   

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