977 resultados para flow cytometry
Resumo:
BACKGROUND: Previous publications have documented the damage caused to red blood cells (RBCs) irradiated with X-rays produced by a linear accelerator and with gamma rays derived from a Cs-137 source. The biologic effects on RBCs of gamma rays from a Co-60 source, however, have not been characterized. STUDY DESIGN AND METHODS: This study investigated the effect of 3000 and 4000 cGy on the in vitro properties of RBCs preserved with preservative solution and irradiated with a cobalt teletherapy unit. A thermal device equipped with a data acquisition system was used to maintain and monitor the blood temperature during irradiation. The device was rotated at 2 r.p.m. in the irradiation beam by means of an automated system. The spatial distribution of the absorbed dose over the irradiated volume was obtained with phantom and thermoluminescent dosimeters (TLDs). Levels of Hb, K+, and Cl- were assessed by spectrophotometric techniques over a period of 45 days. The change in the topology of the RBC membrane was investigated by flow cytometry. RESULTS: Irradiation caused significant changes in the extracellular levels of K+ and Hb and in the organizational structure of the phospholipid bilayer of the RBC membrane. Blood temperature ranged from 2 to 4 degrees C during irradiation. Rotation at 2 r.p.m. distributed the dose homogeneously (92%-104%) and did not damage the RBCs. CONCLUSIONS: The method used to store the blood bags during irradiation guaranteed that all damage caused to the cells was exclusively due to the action of radiation at the doses applied. It was demonstrated that prolonged storage of Co-60-irradiated RBCs results in loss of membrane phospholipids asymmetry, exposing phosphatidylserine (PS) on the cells` surface with a time and dose dependence, which can reduce the in vivo recovery of these cells. A time- and dose-dependence effect on the extracellular K+ and plasma-free Hb levels was also observed. The magnitude of all these effects, however, seems not to be clinically important and can support the storage of irradiated RBC units for at last 28 days.
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This study aims to evaluate the production of cytokines, tumor necrosis factor (TNF), and interleukin 10 (IL-10) in peripheral blood mononuclear cells (PBMCs) from type 1 diabetic (T1D) patients by means of intracellular staining, flow cytometry, and ELISA and to correlate it with inadequate (IN) and adequate (A) metabolic controls. We studied 28 patients with T1D and 20 healthy individuals (C) paired by sex and age. T1D patients were divided in patients with IN and A metabolic control. PBMC cultures were stimulated with LPS to evaluate TNF or were stimulated with PMA/ionomycin or concanavalin A to evaluate IL-10. The TNF levels in supernatant of stimulated cultures, evaluated by ELISA, of diabetic patients were similar to those of healthy individuals, although the percentage of CD 33(+) cells that were positive for TNF was higher in the T1D IN group compared to the T1D A group (P = 0.01). Similarly, the IL-10 levels evaluated by ELISA in stimulated cultures of T1D patients were not different from those in the control group; moreover, the percentage of CD3(+) cells positive for intracellular IL-10 were higher in the T1D IN group compared to C groups (P = 0.007). The increased levels of cytokines in T1D IN diabetic patients, with reduction in the A group, suggests that hyperglycemia stimulates an inflammatory state that can result in a deficient immune cellular response. The data suggest that assessment by intracellular staining seems to be more accurate than the ELISA technique in evaluating diabetic patients.
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Serious bleeding and thrombotic complications are frequent in acute promyelocytic leukemia (APL) and are major causes of morbidity and mortality. Microparticles (MP) have been used to study the risk and pathogenesis of thrombosis in many malignant disorders. To date, from published articles, this approach had not been applied to APL. In this article, the hemostatic dysfunction in this disorder is briefly reviewed. A study design to address this problem using MP is described. MP bearing tissue factor, profibrinolytic factors (tissue plasminogen activator and annexin A2), and the antifibrinolytic factor plasminogen activator inhibitor type 1 were measured using flow cytometry. The cellular origin of the MP was identified by specific cell surface markers. Comparison of the various populations of MP was made between samples collected at the time of diagnosis with those collected at molecular remission. Preliminary data suggest that this approach is feasible.
Resumo:
Objective. To evaluate the antiinflammatory effects of RC-3095 in 2 experimental models of arthritis, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA), and to determine the mechanisms of action involved. Methods. RC-3095 was administered daily to mice with CIA and mice with AIA, after induction of disease with methylated bovine serum albumin. Disease incidence and severity were assessed using a clinical index and evaluation of histologic features, respectively. In mice with CIA, gastrin-releasing peptide receptor (GRPR) was detected by immunohistochemical analysis, while in mice with AIA, migration of neutrophils, presence of glycosaminoglycans, and lymphocyte proliferation, determined using the MTT assay, were assessed. Expression of cytokines interleukin-17 (IL-17), IL-1 beta, and tumor necrosis factor alpha (TNF alpha) was evaluated in all mouse knees using enzyme-linked immunosorbent assay. Treg cell production was assessed by flow cytometry in the joints of mice with AIA. Results. In mice with AIA, administration of RC-3095 reduced neutrophil migration, mechanical hypernociception, and proteoglycan loss. These findings were associated with inhibition of the levels of all 3 proinflammatory cytokines, decreased lymphocyte proliferation, and increased Treg cell numbers. In the CIA model, treatment with RC-3095 led to a significant reduction in arthritis clinical scores and the severity of disease determined histologically. Synovial inflammation, synovial hyperplasia, pannus formation, and extensive erosive changes were all dramatically reduced in the arthritic mice treated with RC-3095. Furthermore, arthritic mice treated with RC-3095 showed a significant reduction in the concentrations of IL-17, IL-1 beta, and TNF alpha, and showed a diminished expression of GRPR. Conclusion. These findings suggest that the GRP pathway has a significant role in chronic arthritis, and its inhibition can be explored as a possible therapeutic strategy in rheumatoid arthritis.
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Study objective: To compare the effects of ethinylestradiol (EE) and 17 beta-estradiol (E(2)) on nitric oxide (NO) production and protection against oxidative stress in human endothelial cell cultures. Design: Experimental study. Settings: Research laboratory. Material: Human ECV304 endothelial cell cultures. Intervention(s): The NO synthesis was determined by flow cytometry, and oxidative stress was determined by a cell viability assay, after exposure to hydrogen peroxide (H(2)O(2)) and stimulation of endothelial cells with EE at concentrations similar to those of a contraceptive containing 30 mu g EE. Main Outcome Measure(s): The effects of EE were compared with those of E(2) at concentrations similar to those occurring during the follicular phase. Result(s): Ethinylestradiol did not increase NO synthesis and did not protect cells against oxidative stress. The viability of the cells incubated with E(2) in combination with H(2)O(2) was greater than the viability obtained with H(2)O(2) only or with H(2)O(2) in combination with EE. The cells stimulated with E(2) presented a significant increase in NO production compared with control. Conclusion(s): In contrast to the effects of E(2), EE did not protect human ECV304 endothelial cells against oxidative stress and did not increase their production of NO. (Fertil Steril (R) 2010; 94: 1578-82. (C) 2010 by American Society for Reproductive Medicine.)
Resumo:
Chlorhexidine (CHX), widely used as antiseptic and therapeutic agent in medicine and dentistry, has a toxic effect both in vivo and in vitro. The intrinsic mechanism underlying CHX-induced cytotoxicity in eukaryotic cells is, however, still unknown. A recent study from our laboratory has suggested that CHX may induce death in cultured L929 fibroblasts via endoplasmic reticulum (ER) stress. This hypothesis was further tested by means of light and electron microscopy, quantification of apoptosis and necrosis by flow cytometry, fluorescence visualization of the cytoskeleton and endoplasmic reticulum, and evaluation of the expression of 78-kDa glucose-regulated protein 78 (Grp78), a marker of activation of the unfolded protein response (UPR) in cultured L929 fibroblasts. Our finding showing increased Grp 78 expression in CHX-treated cells and the results of flow cytometry, cytoskeleton and endoplasmic reticulum fluorescence visualization, and scanning and transmission electron microscopy allowed us to suggest that CHX elicits accumulation of proteins in the endoplasmic reticulum, which causes ER overload, resulting in ER stress and cell death either by necrosis or apoptosis. It must be pointed out, however, that this does not necessarily mean that ER stress is the only way that CHX kills L929 fibroblasts, but rather that ER stress is an important target or indicator of cell death induced by this drug. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
To identify novel genes involved in the molecular pathogenesis of chronic lymphocytic leukemia (CLL) we performed a serial analysis of gene expression (SAGE) in CLL cells, and compared this with healthy B cells (nCD19(+)). We found a high level of similarity among CLL subtypes, but a comparison of CLL versus nCD19(+) libraries revealed 55 genes that were over-represented and 49 genes that were down-regulated in CLL. A gene ontology analysis revealed that TOSO, which plays a functional role upstream of Fas extrinsic apoptosis pathway, was over-expressed in CLL cells. This finding was confirmed by real-time reverse transcription-polymerase chain reaction in 78 CLL and 12 nCD19(+) cases (P <.001). We validated expression using flow cytometry and tissue microarray and demonstrated a 5.6-fold increase of TOSO protein in circulating CLL cells (P =.013) and lymph nodes (P =.006). Our SAGE results have demonstrated that TOSO is a novel overexpressed antiapoptotic gene in CLL.
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Background. The live attenuated yellow fever (YF) vaccines have been available for decades and are considered highly effective and one of the safest vaccines worldwide. Methods. The impact of YF-17DD-antigens recall on cytokine profiles of YF-17DD-vaccinated children were characterized using short-term cultures of whole blood samples and single-cell flow cytometry. This study enrolled seroconverters and nonseroconverters after primovaccination (PV-PRNT(+) and PV-PRNT(-)), seroconverters after revaccination (RV-PRNT(+)), and unvaccinated volunteers (UV-PRNT(-)). Results. The analysis demonstrated in the PV-PRNT(+) group a balanced involvement of pro-inflammatory/regulatory adaptive immunity with a prominent participation of innate immunity pro-inflammatory events (IL-12(+) and TNF-alpha(+) NEU and MON). Using the PV-PRNT(+) cytokine signature as a reference profile, PV-PRNT(+) presented a striking lack of innate immunity proinflammatory response along with an increased adaptive regulatory profile (IL-4(+) CD4(+) T cells and IL-10(+) and IL-5(+) CD8(+) T cells). Conversely, the RV-PRNT(+) shifted the overall cytokine signatures toward an innate immunity pro-inflammatory profile and restored the adaptive regulatory response. Conclusions. The data demonstrated that the overall cytokine signature was associated with the levels of PRNT antibodies with a balanced innate/adaptive immunity with proinflammatory/regulatory profile as the hallmark of PV-PRNT(MEDIUM+), whereas a polarized regulatory response was observed in PV-PRNT(-) and a prominent proinflammatory signature was the characteristic of PV-PRNT(HIGH+).
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The purpose of the present trial was to compare the percentages of necrotic and apoptotic polymorphonuclear leukocytes (PMNL) in goat milk with low and high somatic cell count (SCC). Twenty eight milk samples were collected from 20 lactating goats, determined to be negative in bacteriological examination, and divided in three groups, according to their SCC: samples with SCC lower than 500 x 10(3) cells/mL; between 500 and 1500 x 10(3) cells/mL; and higher than 1500 x 10(3) cells/m L. SCC was performed in an automatic somatic cell counter. Apoptosis and necrosis were quantified using dual-color flow cytometry with fluorescein labeled annexin-V and propidium iodide (PI). Results of the present study showed a significant positive correlation between the percentage of the viable PMNL and milk SCC(r = 0.495, P=0.008), as well as a significant negative correlation between apoptotic PMNL and milk SCC(r = -0.486, P = 0.009). Results also pointed out lower PMNL viability rates due to higher apoptosis rates in milk samples with SCC lower than 5 x 10(5) cells/mL. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
Objectives: In this work, we searched for maternal separation effects on serum corticosterone levels and blood neutrophil activity in adult male A/J and C57BL/6 mouse offspring. Methods: 40 male A/J mice and 40 male C57BL/6 mice were divided within each strain into two groups. Mice in the maternal separation group were separated from their mothers (1 h/day) on postnatal days 0-13. Mice in the control group were left undisturbed. On postnatal day 45, blood was drawn from all mice and used to assess neutrophil activity by flow cytometry and serum corticosterone levels by radioimmunoassay. Results: The results showed that each mouse strain responded differently to maternal separation, but in both cases, serum corticosterone levels were affected. In both strains, adult mice that experienced maternal separation showed lower serum corticosterone levels than control mice. In relation to control mice kept together with their mothers, the levels of serum corticosterone were 72.7 and 36.36% lower in A/J and C57BL/6 mice submitted to maternal separation, respectively. The current findings showed that maternal separation increased neutrophil activity in mice after reaching adulthood. The observed effects, although in the same direction, differed between A/J and C57BL/6 mice. Maternal separation increased both the percentage and intensity of phagocytosis in C57BL/6 mice, but had no effects on A/J mice. Furthermore, maternal separation increased basal and propidium iodide-labeled Staphylococcus aureus-induced oxidative burst in A/J mice but did not affect oxidative burst in C57BL/6 mice. Finally, phorbol myristate acetate-induced oxidative burst increased in both strains. Conclusion: These results indicate that early maternal separation increases innate immunity, most likely by modifying hypothalamus-pituitary-adrenal axis activity. This suggests that maternal separation is a good model for stress which produces long-term neuroimmune changes whatever the animal species and strain used. Copyright (C) 2011 S. Karger AG, Basel
Resumo:
Cohabitation for 14 days with an Ehrlich tumor-bearing mice was shown, among others, to increase locomotor activity, and hypothalamic noradrenaline levels and turnover, to decrease the innate immune responses and animal resistance to tumor growth. The present experiment was designed to access the relevance of tactile, olfactory, and visual communication to the neuroimmune changes induced by cohabitation with a tumor-bearing partner. Mice that were not allowed to perceive odor cues from their sick partners presented no alterations in neutrophil activity, a fact not observed after visual deprivation and physical isolation. Mice use scents for intraspecies communication in many social contexts. Tumors produce volatile organic compounds released into the atmosphere through breath, sweat, and urine. The present results strongly suggest that volatile compounds released by Ehrlich tumor-injected mice are perceived by their conspecifics, inducing the neuroimmune changes reported for cohabitation with a sick companion. (C) 2010 Published by Elsevier B.V.
Resumo:
Objective: Prolactin (PRL), a peptide hormone produced by the pituitary gland, is involved in the interaction between the neuroendocrine and immune system. Since dopamine receptor antagonists increase serum levels of PRL, both PRL and dopamine receptors might be involved in the modulation of macrophage activity, providing means of communication between the nervous and immune systems. This study evaluated the effects of PRL and the dopamine antagonist domperidone (DOMP) on macrophage activity of female rats. Methods: Oxidative burst and phagocytosis of peritoneal macrophages were evaluated by flow cytometry. Samples of peritoneal liquid from female rats were first incubated with PRL (10 and 100 nM) for different periods. The same procedure was repeated to evaluate the effects of DOMP (10 and 100 nM). Results: In vitro incubation of macrophages with 10 nM DOMP decreased oxidative burst, after 30 min, whereas the PMA-induced burst was decreased by DOMP 10 nM after 2 and 4 h. Treatment with PRL (10 and 100 nM) for 30 min decreased oxidative burst and rate of phagocytosis (10 nM). After 2 h of incubation, 10 nM PRL decreased oxidative burst and phagocytosis intensity, but increased the rate of phagocytosis. On the other hand, after 4 h, PRL 10 and 100 nM increased oxidative burst and the rate of phagocytosis, but decreased intensity of phagocytosis. Conclusions: These observations suggest that macrophage functions are regulated by an endogenous dopaminergic tone. Our data also suggest that both PRL and dopamine exert their action by acting directly on the peritoneal macrophage. Copyright (C) 2008 S. Karger AG, Basel.
Resumo:
The present study was designed to evaluate the effects of mice cohabitation with a sick conspecific cage mate on peritoneal macrophage activity and on resistance to Ehrlich tumor growth. Female mice housed in pairs were divided into control and experimental groups. One mouse of each control pair was inoculated with NaCl (0.1 ml/10 g) intraperitoneally and the other, called `companion of healthy partner` (CHP), was kept undisturbed. One animal of each experimental pair of mice was inoculated with 5.0 x 10(6) Ehrlich tumor cells intraperitoneally and the other, the subject of this study, was called `companion of sick partner` (CSP). Peritoneal macrophages were removed from CSP and CHP mice to analyze resident macrophage activity (experiment 1), macrophage activity after Mycobacterium bovis (experiment 2) or Ehrlich tumor cells (experiment 3) in vivo inoculations. The resistance of CSP and CHP mice to Ehrlich tumor growth was also analyzed (experiment 4). Differences between groups were not found on resident macrophage activity. However, Onco-BCG- and Ehrlich tumor-activated macrophages from CSP mice presented a decreased intensity and percentage of phagocytosis and an increased respiratory burst in the presence of Staphylococcus aureus stimulation in vitro. CSP animals at the same time displayed a decreased resistance to Ehrlich tumor growth. These data were discussed in light of a possible psychological stress effect imposed by the housing condition on mice`s peritoneal macrophage activity and, as a consequence, on their resistance to Ehrlich tumor growth. Copyright (c) 2008 S. Karger AG, Basel.
Resumo:
Sperm-mediated gene transfer (SMGT) is a fast and low-cost method used to produce transgenic animals. The objective of this study was to evaluate the effects of the concentration of exogenous DNA and the duration of incubation on DNA uptake by bovine spermatozoa and subsequently the integrity of sperm DNA and sperm apoptosis. Spermatozoa (5 X 10(6) cells/mL) were incubated with 100, 300, or 500 ng of exogenous DNA (pEYFP-Nuc plasmid) for 60 or 120 min at 39 degrees C. The amount of exogenous DNA associated with spermatozoa was quantified by real-time PCR, and the percentages of DNA fragmentation in spermatozoa were evaluated using SCSA and a TUNEL assay, coupled with flow cytometry. Uptake of exogenous DNA increased significantly as incubation increased from 60 to 120 min (0.0091 and 0.028 ng, respectively), but only when the highest exogenous DNA concentration (500 ng) was used (P < 0.05). Based on SCSA and TUNEL assays, there was no effect of exogenous DNA uptake or incubation period on sperm DNA integrity. In conclusion, exogenous DNA uptake by bovine spermatozoa was increased with the highest exogenous DNA concentration and longest incubation period, but fragmentation of endogenous DNA was apparently not induced. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
The process of cryopreservation impairs sperm cell function, potentially leading to a reduction in fertility. The objectives of the present study were to evaluate the effects that cryopreservation using two different extenders has on sperm motility and mitochondrial function, as well as on the integrity of plasma membranes, acrosomal membranes and chromatin, using practical and objective techniques. The focus of the present study was to identify correlations between alterations in sperm membranes and sperm motility in cryopreserved bovine spermatozoa. Seven ejaculates were collected from eight Simmental bulls (n = 56). After collection, semen volume and concentration were assessed for purposes of dilution. Sperm motility was evaluated subjectively and by computer-assisted semen analysis, morphological characteristics were evaluated by differential interference microscopy, the integrity of plasma and acrosomal membranes, as well as mitochondrial function, were determined using a combination of fluorescent probes containing fluorescein isothiocyanate-Pisum sativum agglutinin, propidium iodide or 5,5`,6,6`-tetrachloro-1,1`,3,3`-tetraethylbenzimidazolearbocyanine iodide. Chromatin integrity was evaluated using the acridine orange technique. The semen was subsequently divided into two aliquots and diluted with one of two extenders (Bioxcell(R) or Botu-Bov(R)), after which both were packaged in 0.5 mL straws and frozen using an automated system. Two straws of semen from each treatment were thawed, and the semen parameters were evaluated as described above. Cryopreservation of sperm reduced motility, damaging plasma and acrosomal membranes, as well as decreasing mitochondrial function. The Botu-Bov(R) extender was more effective in preserving sperm motility and membrane integrity than was the Bioxcell(R) extender. (C) 2007 Elsevier B.V. All rights reserved.