116 resultados para Acid-induced Immunosuppression


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Introduction Maternal folic acid deficiency is the most important metabolic factor in the etiology of neural tube defects (NTD) and is reduced by ethanol, which is extensively consumed by young women. Objective The objective of the study was to determine whether folic acid supplementation in dietary saccharose is efficient in the prevention NTD induced by ethanol in fetuses of Swiss mice. Materials and methods Pregnant mice were divided into four groups of six animals each: control (C), ethanol (E), deficient-supplemented (DS), and deficient-supplemented+ethanol (DSE). Groups C and E received commercial mouse chow (containing 3 mg/kg folic acid) throughout the experiment, while groups DS and DSE received a folic acid-free diet with the addition of saccharose supplemented with folic acid (2 mg/kg folic acid) in water. Group E and DSE animals received ethanol (4 g/kg) administered intraperitoneally from the seventh to the ninth gestational day (gd) and were euthanized on the 18th gd, while groups C and DS received saline. Results Congenital anomalies were observed in groups E and DSE. The fetal weight and length of the animals in group E were lower than in groups C and DS and, in group DSE, were lower than in groups C and DS. The placental diameter of group E was smaller than that of group C, and the placental weight of group C animals was lower than that of groups E, DSE, and DS. Conclusion The study demonstrated that dietary supplementation with folate in saccharose is an accessible means of consumption that could be further diffused but in an increased dose than recommended to reduce the teratogenic effects of ethanol.

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We analyzed the effect of (+)alpha-tocopheryl succinate (alpha-TOS) alone or associated with arsenic trioxide (ATO) or all-trans retinoid acid (ATRA) in acute promyelocytic leukemia (APL). alpha-TOS-induced apoptosis in APL clinical samples and in ATRA-sensitive (NB4) and ATRA-resistant (NB4-R2) APL cell lines. The effective dose 50% (ED-50) was calculated to be 71 and 58 mu M, for NB4 and NB4-R2, respectively. a-TOS neither induced nor modified ATRA-induced differentiation of APL cells, and did not affect the proliferation and differentiation of normal CD34(+) hematopoietic progenitors in methylcellulose assays. alpha-TOS exerted a moderate antagonistic effect to ATO-induced apoptosis when treatment was done simultaneously but when alpha-TOS was added 24 h after ATO, an additive effect was observed. Our results support the concept of alpha-TOS as an anti-leukemic compound which spares normal hematopoiesis. (C) 2008 Elsevier Ltd. All rights reserved.

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Among the possible mechanisms explaining the worsening of asthma due to gastroesophageal reflux disease (GERD) is the increase in bronchial hyperresponsiveness. The effects of GERD on bronchial hyperresponsiveness in patients with bronchial asthma have yet to be studied in significant detail. The aim of this study was to determine the effects of esophageal acid perfusion on bronchial responsiveness to bradykinin in patients with both asthma and GERD. In 20 patients with asthma and GERD disease, esophageal pH was monitored with a pH meter and bronchial responsiveness was evaluated by aerosol inhalation of bradykinin during esophageal acid perfusion and, 24 h earlier or later the patients were submitted to another bronchial provocation test without acid infusion. No significant changes were observed in FEV1, FEF25-75%, FVC, or PEF during acid perfusion. The response to the bronchial provocation test did not differ between the control day and the day of acid infusion (p = 0.61). The concentration provoking a 20% fall in FEV1 (geometric mean +/- geometric SD) was 1.09 +/- 5.84 on the day of acid infusion and 0.98 +/- 5.52 on the control day. There is no evidence that acid infusion changes bronchial responsiveness to bradykinin. These findings strongly question the significance of acid infusion as a model to study the pathogenesis of GERD-induced asthma.

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We evaluated the involvement of dorsal hippocampus (DH) 5-HT1A receptors in the mediation of the behavioral effects caused by the pharmacological manipulation of 5-HT neurons in the median raphe nucleus (MRN). To this end, we used the rat elevated T-maze test of anxiety. The results showed that intra-DH injection of the 5-HT1A/7 agonist 8-OH-DPAT facilitated inhibitory avoidance, an anxiogenic effect, without affecting escape. Microinjection of the 5-HT1A antagonist WAY-100635 was ineffective. In the elevated T-maze, inhibitory avoidance and escape have been related to generalized anxiety and panic disorders, respectively. Intra-MRN administration of the excitatory aminoacid kainic acid, which non-selectively stimulates 5-HT neurons in this brain area facilitated inhibitory avoidance and impaired escape performance, but also affected locomotion. Intra-MRN injection of WAY-100635, which has a disinhibitory effect on the activity of 5-HT neurons in this midbrain area, only facilitated inhibitory avoidance. Preadministration of WAY-100635 into the DH blocked the behavioral effect of intra-MRN injection of WAY-100635, but not of kainic acid. These results indicate that DH 5-HT1A receptors mediate the anxiogenic effect induced by the selective stimulation of 5-HT neurons in the MRN. (c) 2007 Elsevier B.V. and ECNP. All rights reserved.

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Hematopoietic SCT (HSCT) and high-dose chemotherapy are being explored as therapy for various human refractory immune-mediated conditions, including inflammatory bowel diseases (IBD). Nevertheless, the exact immunological mechanisms by which the BM cells (BMCs) or immunosuppression provide remission from these diseases is not yet clear. In this work, we investigated the role of these therapies in the modulation of gut mucosal inflammation in an experimental model of IBD. Colitis was induced in mice by 2,4,6-trinitrobenzenesulfonic acid and after CY was administered (200 mg/kg) alone (CY group) or followed by BMCs infusion (HSCT group). Animals were followed for 60 days. Both HSCT and CY reduced the histopathological features of colitis significantly. Infused cells were localized in the gut, and a marked decrease of CD4(+) leukocytes in the inflammatory infiltrate on days +7 and +14 and of CD8(+) cells on day +7 was found in both treatments allied to impressive reduction of proinflammatory Th1 and Th17 cytokines. Although chemotherapy alone was the best treatment regarding the induction of immunosuppressive molecules, only HSCT resulted in increased survival rates compared with the control group. Our findings indicate that high-dose CY followed by HSCT is effective in the modulation of mucosal immunity and in accelerating immune reconstitution after BMT, thus providing valuable tools to support the development and understanding of novel therapeutic strategies for IBD. Bone Marrow Transplantation (2010) 45, 1562-1571; doi:10.1038/bmt.2010.6; published online 15 March 2010

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BACKGROUND AND PURPOSE Lipoxin A(4) (LXA(4)) is a lipid mediator involved in the resolution of inflammation. Increased levels of LXA(4) in synovial fluid and enhanced expression of the formyl peptide receptor 2/lipoxin A(4) receptor (FPR2/ALX) in the synovial tissues of rheumatoid arthritis patients have been reported. Endothelins (ETs) play a pivotal pro-inflammatory role in acute articular inflammatory responses. Here, we evaluated the anti-inflammatory role of LXA(4), during the acute phase of zymosan-induced arthritis, focusing on the modulation of ET-1 expression and its effects. EXPERIMENTAL APPROACH The anti-inflammatory effects of LXA(4), BML-111 (agonist of FPR2/ALX receptors) and acetylsalicylic acid (ASA) pre- and post-treatments were investigated in a murine model of zymosan-induced arthritis. Articular inflammation was assessed by examining knee joint oedema; neutrophil accumulation in synovial cavities; and levels of prepro-ET-1 mRNA, leukotriene (LT)B(4), tumour necrosis factor (TNF)-alpha and the chemokine KC/CXCL1, after stimulation. The direct effect of LXA(4) on ET-1-induced neutrophil activation and chemotaxis was evaluated by shape change and Boyden chamber assays respectively. KEY RESULTS LXA(4), BML-111 and ASA administered as pre- or post-treatment inhibited oedema and neutrophil influx induced by zymosan stimulation. Zymosan-induced preproET-1 mRNA, KC/CXCL1, LTB(4) and TNF-alpha levels were also decreased after LXA(4) pretreatment. In vitro, ET-1-induced neutrophil chemotaxis was inhibited by LXA4 pretreatment. LXA(4) treatment also inhibited ET-1-induced oedema formation and neutrophil influx into mouse knee joints. CONCLUSION AND IMPLICATION LXA(4) exerted anti-inflammatory effects on articular inflammation through a mechanism that involved the inhibition of ET-1 expression and its effects.

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Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial. or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial. or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour. (C) 2009 Elsevier B.V. All rights reserved.

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The role of alpha-tocopherol during nephrogenesis was investigated in rats subjected to maternal undernutrition, which reduces the number of nephrons. alpha-tocopherol (350 mg/kg, p.o.) was administered daily to well-nourished or malnourished Wistar dams during pregnancy, or to prenatal undernourished rats during lactation. The kidneys of 1- and 25-day-old offspring were removed to evaluate expression of angiotensin II (Ang II) and to correlate this with expression of proliferating cell nuclear antigen, alpha-smooth muscle actin, fibronectin and vimentin in the glomeruli and tubulointerstitial space. One-day-old prenatally undernourished rats had reduced expression of Ang II and of kidney development markers, and presented with an enlarged nephrogenic zone. Maternal administration of alpha-tocopherol restored the features of normal kidney development in undernourished rats. Twenty-five-day-old prenatally undernourished progeny had fewer glomeruli than the control group. Conversely, animals from mothers that received alpha-tocopherol during lactation presented with the same number of glomeruli and the same glomerular morphometrical profile as the control group. Analyzing the levels of thiobarbituric acid reactive substances in the liver in conjunction with kidney development markers, it is plausible that alpha-tocopherol had antioxidant and non-antioxidant actions. This study provides evidence that alpha-tocopherol treatment restored Ang II expression, and subsequently restored renal structural development.

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The hypothalamus-pituitary-adrenal axis (HPA) participates in mediating the response to stressful stimuli. Within the HPA, neurons in the medial parvocellular region of paraventricular nucleus (PVN) of the hypothalamus integrate excitatory and inhibitory signals triggering secretion of corticotropin-releasing hormone (CRH), the main secretagogue of adrenocorticotropic hormone (ACTH). Stressful situations alter CRH secretion as well as other hormones, including prolactin and oxytocin. Most inputs to the PVN are of local origin, half of which are GABAergic neurons, and both GABA-A and GABA-B receptors are present in the PVN. The objective of the present study was to investigate the role of GABA-A and GABA-B receptors in the PVN`s control of stress-induced corticosterone, oxytocin and prolactin secretion. Rats Were microinjected with saline or different doses (0.5, 5 and 50 pmol) of GABA-A (bicuculine) or GABA-B (phaclofen) antagonists in the PVN. Ten minutes later, they were subjected to a stressor (ether inhalation) and blood samples were collected 30 min before and 10, 30, 60, 90 and 120 min after the stressful stimulus to measure hormone levels by radioimmunoassay. Our results indicate that GABA acts in the PVN to inhibit stress-induced corticosterone secretion via both its receptor subtypes, especially GABA-B. In contrast, GABA in the PVN stimulates oxytocin secretion through GABA-B receptors and does not alter prolactin secretion. (C) 2008 Elsevier Inc. All rights reserved.

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Introduction: Inhibition of matrix metalloproteinases (MMPs) improves the hemodynamics during acute pulmonary embolism (APE) and oxidative stress upregulates MMPs. We compared the effects of different NO-cGMP pathway activators on APE-induced increases in MMPs. Materials and Methods: Hemodynamic and biochemical evaluations were performed in non-embolized dogs treated with saline (N = 5), and in microspheres embolized dogs receiving saline (n = 9), or nitrite (6.75 mu mol/kg i.v. over 15 min followed by 0.28 mu mol/kg/min; n = 5), or sildenafil (0.25 mg/kg; n = 5), or BAY 41-2272 (0.03, 0.1, 0.3, and 1 mg/kg/h; n = 5). Plasma thiobarbituric acid reactive substances (TBARS) concentrations were determined. Zymograms of plasma samples were performed, and in vitro antioxidant effects or inhibition of MMPs by these drugs were examined. Results: APE increased mean pulmonary artery pressure by similar to 25 mmHg. Nitrite, BAY 41-2272, or sildenafil reversed this increase by similar to 40% (P < 0.05). Similar effects were seen on the pulmonary vascular resistance. While both nitrite and sildenafil produced no systemic effects, the highest dose of BAY 41-2272 produced systemic hypotension (P<0.05). While nitrite and sildenafil blunted the increases in plasma pro-MMP-9 levels and TBARS (all P < 0.05), BAY 41-2272 produced no such effects. Nitrite and sildenafll produced in vitro antioxidant effects and inhibited MMPs only at high concentrations. BAY 41-2272 produced no such effects. Conclusions: Activation of the NO-cGMP pathway with nitrite or sildenafil, but not with BAY 41-2272, attenuates APE-induced oxidative stress and increased MMP-9 levels. These findings are consistent with the idea that NO-cGMP pathway activators with antioxidant effects prevent the release of MMP-9 during APE. (c) 2008 Elsevier Ltd. All rights reserved.

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Most meningiomas are benign tumours of arachnoidal origin, although a small number have high proliferative rates and invasive properties which complicate complete surgical resection and are associated with increased recurrence rates. Few prognostic indicators exist for meningiomas and further research is necessary to identify factors that influence tumour invasion, oedema and recurrence. Paraffin sections from 25 intracranial meningiomas were analysed for expression of the proteins vascular endothelial growth factor (VEGF), VEGF receptors Flt1 and Flk1, E-cadherin, metalloproteinases 2 and 9 (MMP2, MMP9), CD44, receptor for hyaluronic acid-mediated motility (RHAMM), hyaluronic acid (HA), CD45, cyclooxygenase 2 (COX2), brain fatty acid binding protein (BFABP), Ki67, and proliferating cell nuclear antigen (PCNA). Correlations among protein expression were found for several markers of proliferation (Ki67, PCNA, MI) and microvessel density (MVD). COX2 expression increased with increasing with tumour grade and correlated with Ki67, PCNA, MI, MVD, and BFABP. BFABP expression also correlated with Ki67 and PCNA expression. Relationships were also identified among angiogenic factors (VEGF, Flt1, Flk1) and proliferation markers. Oedema was found to correlate with MMP9 expression and MMP9 also correlated with proliferation markers. No correlations were found for MMP2, E-cadherin, or CD44 in meningiomas. In conclusion Ki67, PCNA, MI, MVD, BFABP, and COX2 were significantly correlated with meningioma tumour grade and with each other. These findings, by correlating both intracellular fatty acid transport and eicosanoid metabolism with tumour proliferation, as determined by Ki67 labelling and mitotic index, suggest fatty acids are involved in the progression of meningiomas.

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Injury triggers inflammatory responses and tissue repair. Several treatments are currently in use to accelerate healing: however, more efficient formulations are still needed for specific injuries. Since unsaturated fatty acids modulate immune responses, we aimed to evaluate their therapeutic effects on wound healing. Skin wounds were induced in BALB/c mice and treated for 5 days with n-3, n-9 fatty acids or vehicle (control). n-9 treated mice presented smaller wounds than control and n-3 at 120 h post-surgery (p.s.). Collagen III mRNA,TIMP1 and MMP9 were significantly elevated in n-9 group compared to n-3 or vehicle at 120 h p.s. Among the inflammatory mediators studied we found that IL-10, TNF-alpha and IL-17 were also higher in n-9 treated group compared to n-3 or vehicle at 120 h p.s. Interestingly, COX2 had decreased expression on wound tissue treated with n-9. Inflammatory infiltrate analysis revealed diminished frequency of CD4(+), CD8(+) and CD11b(+) cells in n-9 wounds at 24 and 120 h p.s., which was not related to cell death, since in vitro apoptosis experiments did not show any cell damage after fatty acids administration. These results suggested that unsaturated fatty acids, specifically n-9, modulate the inflammation in the wound and enhance reparative response in vivo. n-9 may be a useful tool in the treatment of cutaneous wounds. (C) 2010 Elsevier GmbH. All rights reserved.

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An L-amino acid oxidase (BjarLAAO-I) from Bothrops jararaca snake venom was highly purified using a stepwise sequential chromatography on Sephadex G-75, Benzamidine Sepharose and Phenyl Sepharose. Purified BjarLAAO-I showed a molecular weight around 60,000 under reducing conditions and about 125,000 in the native form, when analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively. BjarLAAO-I is a homodimeric acidic glycoprotein, pI similar to 5.0, and N-terminal sequence showing close structural homology with other snake venom LAAOs. The purified enzyme catalysed the oxidative deamination of L-amino acids, the most specific substrate being L-Phe. Five amino acids, L-Ser, L-Pro, L-Gly, L-Thr and L-Cys were not oxidized, clearly indicating a significant specificity. BjarLAAO-I significantly inhibited Ehrlich ascites tumour growth and induced an influx of polymorphonuclear cells, as well as spontaneous liberation of H(2)O(2) from peritoneal macrophages. Later, BjarLAAO-I induced mononuclear influx and peritoneal macrophage spreading. Animals treated with BjarLAAO-I showed higher survival time.

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Positive end-expiratory pressure (PEEP) and sustained inspiratory insufflations (SI) during acute lung injury (ALI) are suggested to improve oxygenation and respiratory mechanics. We aimed to investigate the hemodynamic effects of PEEP with and without alveolar recruiting maneuver in a mild ALI model induced by inhalation of hydrochloric acid. Thirty-two pigs were randomly allocated into four groups (Control-PEEP, Control-SI, ALI-PEEP and ALI-SI). ALI was induced by intratracheal instillation of hydrochloric acid. PEEP values were progressively increased and decreased from 5, 10, 15 and 20 cmH(2)O in all groups. Three SIs maneuvers of 30 cmH(2)O for 20 s were applied to the assignable groups between each PEEP level. Transesophageal echocardiography (TEE), global hemodynamics, oxygenation indexes and gastric tonometry were measured 5 min after the maneuvers had been concluded and at each established value of PEEP (5, 10, 15 and 20 cmH(2)O). The cardiac index, ejection fraction and end-diastolic volume of right ventricle were significantly (P < 0.001) decreased with PEEP in both Control and ALI groups. Left ventricle echocardiography showed a significant decrease in end-diastolic volume at 20 cmH(2)O of PEEP (P < 0.001). SIs did not exert any significant hemodynamic effects either early (after 5 min) or late (after 3 h). In a mild ALI model induced by inhalation of hydrochloric acid, significant hemodynamic impairment characterized by cardiac function deterioration occurred during PEEP increment, but SI, probably due to low applied values (30 cmH(2)O), did not exert further negative hemodynamic effects. PEEP should be used cautiously in ALI caused by acid gastric content inhalation.

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The aims of this study were: (1) to correlate surface (SH) and cross-sectional hardness (CSH) with microradiographic parameters of artificial enamel lesions; (2) to compare lesions prepared by different protocols. Fifty bovine enamel specimens were allocated by stratified randomisation according to their initial SH values to five groups and lesions produced by different methods: MC gel (methylcellulose gel/lactic acid, pH 4.6, 14 days); PA gel (polyacrylic acid/lactic acid/hydroxyapatite, pH 4.8, 16 h); MHDP (undersaturated lactate buffer/methyl diphosphonate, pH 5.0, 6 days); buffer (undersaturated acetate buffer/fluoride, pH 5.0, 16 h), and pH cycling (7 days). SH of the lesions (SH(1)) was measured. The specimens were longitudinally sectioned and transverse microradiography (TMR) and CSH measured at 10- to 220-mu m depth from the surface. Overall, there was a medium correlation but non-linear and variable relationship between mineral content and root CSH. root SH(1) was weakly to moderately correlated with surface layer properties, weakly correlated with lesion depth but uncorrelated with integrated mineral loss. MHDP lesions showed the highest subsurface mineral loss, followed by pH cycling, buffer, PA gel and MC gel lesions. The conclusions were: (1) CSH, as an alternative to TMR, does not estimate mineral content very accurately, but gives information about mechanical properties of lesions; (2) SH should not be used to analyse lesions; (3) artificial caries lesions produced by the protocols differ, especially considering the method of analysis. Copyright (C) 2009 S. Karger AG, Basel