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النتائج 371 - 380 من 463
Immunostimulatory effects of BCG-CWS on the proliferation and viability of mouse spleen cells
2012
Lee, C.W., Jeju National University, Jeju, Republic of Korea | Ko, E.J., Jeju National University, Jeju, Republic of Korea | Joo, H.G., Jeju National University, Jeju, Republic of Korea
Mycobacterial cell-wall skeleton (CWS) is an immunoactive and biodegradable particulate adjuvant and has been tried to use for immunotherapy. The CWS of Mycobacterium bovis bacillus Calmette-Guerin (BCG-CWS) was studied as an universal vaccine vehicle for antigen conjugation, to develop potentially effective and safe vaccine. Although a variety of biological activities of BCG-CWS have been studied, the effects of BCG-CWS on spleen cells are not fully elucidated. Using MTT assay and trypan blue exclusion test, we found that BCG-CWS significantly enhanced the viability and proliferation of cells. Multiple clusters, indicating proliferation, were observed in BCG-CWS-treated spleen cells and surface marker staining assay revealed that BCG-CWS promoted the proliferation of CD19+ B lymphocyte rather than CD4+ or CD8+ T lymphocyte. In addition, BCG-CWS up-regulated the expression of anti-apoptotic molecules such as bcl-2, bcl-xL. BCG-CWS increased the surface expression of CD25 and CD69 as well as IL-2 production of spleen cells, suggesting increased activation. Furthermore, BCG-CWS enhanced the antigen-specific cell proliferation and interferon-gamma production of spleen cells. Taken together, these results demonstrate the immunostimulatory effects of BCG-CWS on spleen cells via multiple mechanisms, providing valuable information to broaden the use of BCG-CWS in clinical and research settings.
اظهر المزيد [+] اقل [-]Differential gene expression pattern in brains of acrylamide-administered mice
2012
Han, C.H., Jeju National University, Jeju, Republic of Korea
The present study was performed to evaluate the relationship between the neurotoxicity of acrylamide and the differential gene expression pattern in mice. Both locomotor test and rota-rod test showed that the group treated with higher than 30 mg/kg/day of acrylamide caused impaired motor activity in mice. Based on cDNA microarray analysis of mouse brain, myelin basic protein gene, kinesin family member 5B gene, and fibroblast growth factor (FGF) 1 and its receptor genes were down-regulated by acrylamide. The genes are known to be essential for neurofilament synthesis, axonal transport, and neuro-protection, respectively. Interestingly, both FGF 1 and its receptor genes were down-regulated. Genes involved in nucleic acid binding such as AU RNA binding protein/enoyl-coA hydratase, translation initiation factor (TIF) 2 alpha kinase 4, activating transcription factor 2, and U2AF 1 related sequence 1 genes were down-regulated. More interesting finding was that genes of both catalytic and regulatory subunit of protein phosphatases which are important for signal transduction pathways were down-regulated. Here, we propose that acrylamide induces neurotoxicity by regulation of genes associated with neurofilament synthesis, axonal transport, neuro-protection, and signal transduction pathways.
اظهر المزيد [+] اقل [-]Dietary zinc inhibits the formation of colonic preneoplastic lesion induced by azoxymethane and dextran sodium sulfate in mice
2012
Park, H.J., Chungbuk National University, Cheongju, Republic of Korea | Kim, D.Y., Chungbuk National University, Cheongju, Republic of Korea | Kang, B.S., Chungbuk National University, Cheongju, Republic of Korea | Yoon, J.S., Chungbuk National University, Cheongju, Republic of Korea | Jeong, J.H., Chungbuk Province College, Okcheon, Republic of Korea | Nam, S.Y., Chungbuk National University, Cheongju, Republic of Korea | Yun, Y.W., Chungbuk National University, Cheongju, Republic of Korea | Kim, J.S., Chungbuk National University, Cheongju, Republic of Korea | Lee, B.J., Chungbuk National University, Cheongju, Republic of Korea
Colorectal cancer (CRC) is one of the leading causes of cancer death in western countries or in the developed countries. Zinc intake has been associated with decreased risk of CRC. We investigated the effect of zinc on the formation of colonic aberrant crypt foci (ACF) induced by azoxymethane followed by dextran sodium sulfate in mice. Five-week old ICR mice were fed with the different zinc levels (0.01, 0.1, 1 ppm) for 12 weeks. The numbers of ACF were measured in the colonic mucosa. The ACF number of HZn group was significantly low compared with LZn group or MZn group. Cytosolic superoxide dismutase activity was the highest in HZn group, while thiobarbituric acid reactive substance level for lipid peroxidation was the highest in LZn group. There was no difference in number of PCNA-positive proliferative cells among the groups. TUNEL-positive apoptotic cells were increased in HZn group compared with LZn group. The HZn group exhibited a decrease of β-catenin immunostaining areas compared with the LZn or MZn group. These findings indicate that dietary zinc might exert a protecting effect against colon carcinogenesis by inhibiting the development of ACF in the mice.
اظهر المزيد [+] اقل [-]Comparison of Porcine circovirus type 2 (PCV2) infection in light and heavy pigs of market age on farms with routine PCV2 vaccination
2012
Lyoo, Kwang-Soo | Joo, Han Soo | Davies, Peter R. | Han, Jeong Hee
Commercial vaccines against Porcine circovirus type 2 (PCV2) are widely used on swine farms. Marked body weight variation at marketing age is a problem on conventional pig farms using all-in/all-out barn management. The aim of this study was to investigate whether PCV2 infection could be a factor influencing body weight variation. Seven conventional farms that routinely used PCV2 vaccination were selected, and 60 serum samples from light and heavy pigs at each site were tested for PCV2 antibody titers and viremia. At 3 farms the mean antibody titer, proportion of viremic pigs, and virus load differed significantly between the light and heavy groups. These preliminary results suggest that PCV2 infection may be a factor contributing to weight variation in vaccinated market-age hogs.
اظهر المزيد [+] اقل [-]Hypercapnic respiratory acidosis: A protective or harmful strategy for critically ill newborn foals?
2012
Vengust, Modest
This paper reviews both the beneficial and adverse effects of permissive hypercapnic respiratory acidosis in critically ill newborn foals. It has been shown that partial carbon dioxide pressure (PCO2) above the traditional safe range (hypercapnia), has beneficial effects on the physiology of the respiratory, cardiovascular, and nervous system in neonates. In human neonatal critical care medicine permissive hypercapnic acidosis is generally well-tolerated by patients and is more beneficial to their wellbeing than normal carbon dioxide (CO2) pressure or normocapnia. Even though adverse effects of hypercapnia have been reported, especially in patients with central nervous system pathology and/or chronic infection, critical care clinicians often artificially increase PCO2 to take advantage of its positive effects on compromised neonate tissues. This is referred to as therapeutic hypercapnia. Hypercapnic respiratory acidosis is common in critically ill newborn foals and has traditionally been considered as not beneficial. A search of online scientific databases was conducted to survey the literature on the effects of hypercapnia in neonates, with emphasis on newborn foals. The dynamic status of safety levels of PCO2 and data on the effectiveness of different carbon dioxide levels are not available for newborn foals and should be scientifically determined. Presently, permissive hypercapnia should be implemented or tolerated cautiously in compromised newborn foals and its use should be based on relevant data from adult horses and other species.
اظهر المزيد [+] اقل [-]Effects of selenium source on measures of selenium status and immune function in horses
2012
Montgomery, Julia B. | Wichtel, Jeffrey J. | Wichtel, Maureen G. | McNiven, Mary A. | McClure, J T. | Markham, Fred | Horohov, David W.
The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.
اظهر المزيد [+] اقل [-]Evaluation of a novel suture material for closure of intestinal anastomoses in canine cadavers
2012
Hansen, Lane A. | Monnet, Eric L.
Objective: To compare leakage and maximum intraluminal pressures for a novel suture material with pressures for comparable suture material when used in closure of intestinal anastomoses in canine cadavers. Sample: Healthy intestines from cadavers of dogs euthanized for reasons unrelated to the study. Procedures: 18 anastomoses were performed on intestinal sections within 72 hours after dogs were euthanized and intestinal samples collected. Anastomoses were performed with a simple continuous suture pattern. Leakage and maximum intraluminal pressures were measured and recorded for 6 control segments and 18 anastomosed sections. A barbed glycomer 631 suture (size 4–0 United States Pharmacopeia [USP]) was compared with glycomer 631 sutures (sizes 3–0 and 4–0 USP). Results for leakage and maximum intraluminal pressures were compared via an ANOVA. Results: The barbed glycomer 631 suture material leaked at a significantly higher pressure than did the comparable glycomer 631 suture materials. Maximum intraluminal pressures were not significantly different among the suture materials. Conclusions and Clinical Relevance: Barbed glycomer 631 4–0 USP suture material was as effective as glycomer 631 suture materials and may be a safe alternative for use in closure of enterectomies in dogs.
اظهر المزيد [+] اقل [-]Plasma 25-hydroxyvitamin D3 concentrations in Hermann's tortoises (Testudo hermanni) exposed to natural sunlight and two artificial ultraviolet radiation sources
2012
Selleri, Paolo | Di Girolamo, Nicola
Objective: To determine the effect of various UVB radiation sources on plasma 25-hydroxyvitamin D3 concentrations in Hermann's tortoises (Testudo hermanni). Animals: 18 healthy Hermann's tortoises. Procedures: Tortoises were exposed to sunlight in an outdoor enclosure located in the natural geographic range of Hermann's tortoises (n = 6 tortoises) or a self-ballasted mercury-vapor lamp (6) or fluorescent UVB-emitting lamp (6) in an indoor enclosure for 35 days. Plasma samples were obtained from each tortoise on the first (day 0) and last (day 35) days of the study, and concentrations of 25-hydroxyvitamin D3 were determined. Amount of UVB radiation in enclosures was measured. Results: Mean ± SD plasma 25-hydroxyvitamin D3 concentrations for tortoises exposed to the mercury-vapor and fluorescent lamps were significantly lower on day 35 (155.69 ± 80.71 nmol/L and 134.42 ± 51.42 nmol/L, respectively) than they were on day 0 (368.02 ± 119.34 nmol/L and 313.69 ± 109.54 nmol/L, respectively). Mean ± SD plasma 25-hydroxyvitamin D3 concentration for tortoises exposed to sunlight did not differ significantly between days 0 (387.74 ± 114.56 nmol/L) and 35 (411.51 ± 189.75 nmol/L). Mean day 35 plasma 25-hydroxyvitamin D3 concentration was significantly higher for tortoises exposed to sunlight versus those exposed to mercury-vapor or fluorescent lamps. Sunlight provided significantly more UVB radiation than did the mercury-vapor or fluorescent lamps. Conclusions and Clinical Relevance: Plasma 25-hydroxyvitamin D3 concentrations differed between tortoises exposed to sunlight and those exposed to artificial UVB sources. Exposure to sunlight at a latitude similar to that of the natural geographic range is recommended for healthy and calcium-deficient tortoises.
اظهر المزيد [+] اقل [-]Mechanical and morphological properties of trabecular bone samples obtained from third metacarpal bones of cadavers of horses with a bone fragility syndrome and horses unaffected by that syndrome
2012
Symons, Jennifer E. | Entwistle, Rachel C. | Arens, Amanda M. | Garcia, Tanya C. | Christiansen, Blaine A. | Fyhrie, David P. | Stover, Susan M.
Objective: To determine morphological and mechanical properties of trabecular bone of horses with a bone fragility syndrome (BFS; including silicate-associated osteoporosis). Sample: Cylindrical trabecular bone samples from the distal aspects of cadaveric third metacarpal bones of 39 horses (19 horses with a BFS [BFS bone samples] and 20 horses without a BFS [control bone samples]). Procedures: Bone samples were imaged via micro-CT for determination of bone volume fraction; apparent and mean mineralized bone densities; and trabecular number, thickness, and separation. Bone samples were compressed to failure for determination of apparent elastic modulus and stresses, strains, and strain energy densities for yield, ultimate, and failure loads. Effects of BFS and age of horses on variables were determined. Results: BFS bone samples had 25% lower bone volume fraction, 28% lower apparent density, 18% lower trabecular number and thickness, and 16% greater trabecular separation versus control bone samples. The BFS bone samples had 22% lower apparent modulus and 32% to 33% lower stresses, 10% to 18% lower strains, and 41 % to 52% lower strain energy densities at yield, ultimate, and failure loads, compared with control bone samples. Differences between groups of bone samples were not detected for mean mineral density and trabecular anisotropy. Conclusions and Clinical Relevance: Results suggested that horses with a BFS had osteopenia and compromised trabecular bone function, consistent with bone deformation and pathological fractures that develop in affected horses. Effects of this BFS may be systemic, and bones other than those that are clinically affected had changes in morphological and mechanical properties.
اظهر المزيد [+] اقل [-]Use of the oxygen content–based index, Fshunt, as an indicator of pulmonary venous admixture at various inspired oxygen fractions in anesthetized sheep
2012
Araos, Joaquin D. | Larenza, Paula | Boston, Ray C. | De Monte, Valentina | De Marzo, Carmelinda | Grasso, Salvatore | Haskins, Steve C. | Crovace, Antonio | Staffieri, Francesco
Objective: To evaluate the use of the oxygen content–based index, Fshunt, as an indicator of venous admixture (Qs/Qt) at various fractions of inspired oxygen (Fio2s) in anesthetized sheep undergoing Flung or 2-lung ventilation. Animals: 6 healthy adult female sheep. Procedures: Sheep were anesthetized and administered 5 different Fio2s (0.21, 0.40, 0.60, 0.80, and 1.00) in random order during 2-lung mechanical ventilation. Arterial and mixed venous blood samples were obtained at each Fio2 after a 15-minute stabilization period. Vital capacity alveolar recruitment maneuvers were performed after blood collection. The previously used Fio2 sequence was reversed for sample collection during Flung ventilation. Blood samples were analyzed for arterial, pulmonary end-capillary, and mixed venous oxygen content and partial pressure and for hemoglobin concentration. Oxygen hemoglobin saturation, Qs/Qt, Fshunt, and oxygen tension–based indices (OTIs; including Pao2:Fio2, alveolar-arterial difference in partial pressure of oxygen [Pao2 – Pao2], [Pao2 – Pao2]:Fio2, [Pao2 – Pao2]:Pao2, and Pao2:Pao2) were calculated at each Fio2; associations were evaluated with linear regression analysis, concordance, and correlation tests. Intermethod agreement between Qs/Qt and Fshunt was tested via Bland-Altman analysis. Results: Strong and significant associations and substantial agreement were detected between Fshunt and Qs/Qt. Relationships between OTIs and Qs/Qt varied, but overall correlations were weak. Conclusions and Clinical Relevance: Whereas OTIs were generally poor indicators of Qs/Qt, Fshunt was a good indicator of Qs/Qt at various Fio2s, regardless of the magnitude of Qs/Qt and could be potentially used as a surrogate for Qs/Qt measurements in healthy sheep.
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