990 resultados para proper fraction
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Nitric oxide (NO) is an important effector molecule involved in immune regulation and defense. NO produced by cytokine-activated macrophages was reported to be cytotoxic against the helminth Schistosoma mansoni. Identification and characterization of S. mansoni antigens that can provide protective immunity is crucial for understanding the complex immunoregulatory events that modulate the immune response in schistosomiasis. It is, then, essential to have available defined, purified parasite antigens. Previous work by our laboratory identified a fraction of S. mansoni soluble adult worm antigenic preparation (SWAP), named PIII, able to elicit significant in vitro cell proliferation and at the same time lower in vitro and in vivo granuloma formation when compared either to SEA (soluble egg antigen) or to SWAP. In the present work we report the effect of different in vivo trials with mice on their spleen cells ability to produce NO. We demonstrate that PIII-immunization is able to significantly increase NO production by spleen cells after in vitro stimulation with LPS. These data suggest a possible role for NO on the protective immunity induced by PIII.
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This study was performed in order to define Schistosoma mansoni antigens able to function as modulator agents in BALB/c mice granulomatous hypersensitivity to parasite egg. The antigens P-24, P-35 and P-97 were purified by affinity chromatography from a fraction of S. mansoni adult worm antigenic preparation, denominated PIII, involved in the inhibition of granulomatous response to eggs. Immunization of mice with these antigens, in the presence of Corynebacterium parvum and Al(OH)3 as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system. In vitro blastogenesis assays revealed that purified antigens were able to induce significant proliferation of spleen cells from S. mansoni-infected mice. This protection was correlated to significant decrease in granuloma size induced by PIII. From these results, we concluded that PIII preparation contains antigens capable of mediating protective anti-parasite immunity and down-regulating granulomatous hypersensitivity to S. mansoni eggs.
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Myelination requires a massive increase in glial cell membrane synthesis. Here, we demonstrate that the acute phase of myelin lipid synthesis is regulated by sterol regulatory element-binding protein (SREBP) cleavage activation protein (SCAP), an activator of SREBPs. Deletion of SCAP in Schwann cells led to a loss of SREBP-mediated gene expression involving cholesterol and fatty acid synthesis. Schwann cell SCAP mutant mice show congenital hypomyelination and abnormal gait. Interestingly, aging SCAP mutant mice showed partial regain of function; they exhibited improved gait and produced small amounts of myelin indicating a slow SCAP-independent uptake of external lipids. Accordingly, extracellular lipoproteins partially rescued myelination by SCAP mutant Schwann cells. However, SCAP mutant myelin never reached normal thickness and had biophysical abnormalities concordant with abnormal lipid composition. These data demonstrate that SCAP-mediated regulation of glial lipogenesis is key to the proper synthesis of myelin membrane, and provide insight into abnormal Schwann cell function under conditions affecting lipid metabolism.
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Complex physalin metabolites present in the capsules of the fruit of Physalis angulata L. have been isolated and submitted to a series of assays of antimicrobial activity against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, Neisseria gonorrhoeae ATCC 49226, Escherichia coli ATCC 8739; E. coli ATCC 25922, Candida albicans ATCC 10231 applying different methodologies such as: bioautography, dilution broth, dilution agar, and agar diffusion techniques. A mixture of physalins (pool) containing physalins B, D, F, G inhibit S. aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, and N. gonorrhoeae ATCC 49226 at a concentration of 200 mg/µl, using agar dilution assays. The mixture was inactive against P. aeruginosa ATCC27853, E. coli ATCC 8739; E. coli ATCC 25922, C. albicans ATCC 10231 when applying bioautography assays. Physalin B (200 µg/ml) by the agar diffusion assay inhibited S. aureus ATCC 6538P by ± 85%; and may be considered responsible for the antimicrobial activity.
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A Neospora caninum 17 kDa protein fraction (p17) has been described as an immunodominant antigen (IDA) under reducing and non-reducing conditions. The aim of the present study was to investigate the diagnostic utility of p17 in cattle. In order to achieve this, p17 was purified by electroelution from whole N. caninum tachyzoite soluble extract and a p17-based Western blot (WB-p17) was developed. The p17 recognition was measured by densitometry and expressed as OD values to check the validity of the WB-p17. A total of 131 sera including sequential samples from naturally- and experimentally-infected calves and breeding cattle were analysed by WB-p17 and compared with IFAT using whole formalin-fixed tachyzoites as a reference test. The results obtained highlight the feasibility of using the N. caninum p17 in a diagnostic test in cattle. Firstly, the assay based on the p-17 antigen discriminated between known positive and negative sera from different cattle populations, breeding cattle and calves. Secondly, the p17 antigen detected fluctuations in the antibody levels and seroconversion in naturally- and experimentally-infected cattle. Significant differences in p-17 antigen recognition were observed between naturally infected aborting and non-aborting cattle, as well as significant antibody fluctuations over time in experimentally infected cattle, which varied between groups. Furthermore, the results obtained with WB-p17 are in accordance with the results obtained with the IFAT, as high agreement values were obtained when all bovine subpopulations were included (kappa = 0.86).
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A polysaccharide-rich fraction (ATF) of medicinal mushroom Agaricus brasiliensis was evaluated on the candidacidal activity, H2O2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against Candida albicans yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H2O2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.
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Benznidazole (Bz) and Nifurtimox (Nfx) have been used to treat Chagas disease. As recent studies have de-monstrated cardiotoxic effects of Nfx, we attempted to determine whether Bz behaves similarly. Bz reached the heart tissue of male rats after intragastric administration. No cytosolic Bz nitroreductases were detected, although microsomal NADPH-dependent Bz nitroreductase activity was observed, and appeared to be mediated by P450 reductase. No ultrastructurally observable deleterious effects of Bz were detected, in contrast to the overt cardiac effects previously reported for Nfx. In conclusion, when these drugs are used in chagasic patients, Bz may pose a lesser risk to heart function than Nfx when any cardiopathy is present.
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Introduction : La diminution de la fraction d'éjection après infarctus du myocarde est-elle suffisante pour justifier l'implantation prophylactique de défibrillateur ? Introduction: La diminution de la fraction d'éjection (FE) est un facteur prédictif majeur de mortalité cardiaque chez les patients avec ancien infarctus du myocarde (IM). Les plus récentes études, pour la plupart conduites à la fin des années 90, montrent une diminution de la mortalité post-hospitalière à 10 à 20% par année. Une amélioration de la survie par implantation prophylactique de défibrillateurs a été démontrée chez les patients avec dysfonction myocardique avancée après ancien IM dans la cadre de l'étude MADIT II (Multicenter Automatic Defibrillator Implantation Trial) et est depuis lors, considérée comme une thérapie recommandée. Le bénéfice de l'implantation prophylactique de défibrillateurs en terme de nombre nécessaire de patients à traiter pour prévenir un évènement est d'un intérêt primordial en raison des complications potentielles liées à la procédure et l'appareillage, des implications psychologiques ainsi qu'en raison de l'analyse coût-efficacité. Le nombre de patients à traiter est corrélé au risque actuel de mortalité rythmique, probablement influencé par les récentes avancées thérapeutiques dans la prise en charge aigue de l'IM (notamment par angioplastie primaire) et de l'insuffisance cardiaque. Or, dans '' l'étude MADIT II, le recrutement des patients était effectué entre 1997 et 2001 et l'intervalle moyen entre l'IM et le recrutement était de plus de 6 ans. Le but de l'étude était donc d'évaluer, dans la pratique générale, la mortalité actuelle de patients ayant survécu à un IM avec diminution consécutive significative de la FE. La stratification du risque sur la base des variables hospitalières a de même été explorée. Méthode: Une analyse de cohorte de patients avec infarctus aigu du myocarde admis de 1999 à 2000 a été effectuée dans 2 centres hospitaliers (un universitaire et un cantonal). Tous les dossiers cliniques des patients sortis d'hôpital avec FE documentée ≤ 0.40 ont été inclus. Les caractéristiques des patients, les procédures diagnostiques et thérapeutiques ainsi que la médication étaient reportées. La période de suivi débutait à la sortie d'hôpital. Les end-points primaires étaient la mortalité globale, la mortalité cardiaque et les morts subites. Une analyse bivariée et multivariée a été effectuée. Résultats: 165 patients ont été inclus. Durant un suivi médian de 30 mois (interquartile range 22-36), 18 patients sont décédés (5 morts classifiées comme cardiaques, 8 comme subites, 5 de causes non cardiaques). Les taux de mortalité à un et deux ans selon analyse de Kaplan-Meier étaient de 6.7 et 8.6%, respectivement. Les variables reflétant l'atteinte coronarienne et sa prise en charge (antécédent d'IM, reperfusion aigue, revascularisation complète) étaient plus significativement associées à la mortalité comparées aux variables reflétant la dysfonction myocardique (FE, classe Killip à l'admission). Conclusion : La mortalité des patients ayant survécu à un IM avec dysfonction myocardique avancée a diminué de façon substantielle depuis la fin des années 90. La diminution de la mortalité rythmique implique une augmentation proportionnelle du nombre de patients à traiter par implantation de défibrillateur pour prévenir un évènement. Par ailleurs, une stratification du risque après IM basée uniquement sur la FE semble être inappropriée au vu de son impact mineur sur la mortalité comparé aux autres facteurs de risque identifiés dans notre étude. Les patients sans antécédents d'infarctus et ceux ayant bénéficié d'une revascularisation aigue ou complète avait une mortalité cumulée à 2 ans de, respectivement, 2.5%, 3.9% et 2.3%. Pour ce type de patients à bas risque le bénéfice de l'implantation prophylactique de défibrillateur doit être remis en question. Au vu de cette étude, une stratification additionnelle du risque avant implantation de défibrillateur est à considérer.
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Obesity-induced chronic inflammation leads to activation of the immune system that causes alterations of iron homeostasis including hypoferraemia, iron-restricted erythropoiesis, and finally mild-to-moderate anaemia. Thus, preoperative anaemia and iron deficiency are common among obese patients scheduled for bariatric surgery (BS). Assessment of patients should include a complete haematological and biochemical laboratory work-up, including measurement of iron stores, vitamin B12 and folate. In addition, gastrointestinal evaluation is recommended for most patients with iron-deficiency anaemia. On the other hand, BS is a long-lasting inflammatory stimulus in itself and entails a reduction of the gastric capacity and/or exclusion from the gastrointestinal tract which impair nutrients absorption, including dietary iron. Chronic gastrointestinal blood loss and iron-losingenteropathy may also contribute to iron deficiency after BS. Perioperative anaemia has been linked to increased postoperative morbidity and mortality and decreased quality of life after major surgery, whereas treatment of perioperative anaemia, and even haematinic deficiency without anaemia, has been shown to improve patient outcomes and quality of life. However, long-term follow-up data in regard to prevalence, severity, and causes of anaemia after BS are mostly absent. Iron supplements should be administered to patients after BS, but compliance with oral iron is no good. In addition, once iron deficiency has developed, it may prove refractory to oral treatment. In these situations, IV iron (which can circumvent the iron blockade at enterocytes and macrophages) has emerged as a safe and effective alternative for perioperative anaemia management. Monitoring should continue indefinitely even after the initial iron repletion and anaemia resolution, and maintenance IV iron treatment should be provided as required. New IV preparations, such ferric carboxymaltose, are safe, easy to use and up to 1000 mg can be given in a single session, thus providing an excellent tool to avoid or treat iron deficiency in this patient population.
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The present study evaluated the anti-inflammatory and analgesic properties of Agave sisalana Perrine in classic models of inflammation and pain. The hexanic fraction of A. sisalana (HFAS) was obtained by acid hydrolysis followed by hexanic reflux. Anti-inflammatory properties were examined in three acute mouse models (xylene ear oedema, hind paw oedema and pleurisy) and a chronic mouse model (granuloma cotton pellet). The antinociceptive potential was evaluated in chemical (acetic-acid) and thermal (tail-flick and hot-plate test) models of pain. When given orally, HFAS (5, 10, 25 and 50 mg/kg) reduced ear oedema (p < 0.0001; 52%, 71%, 62% and 42%, respectively). HFAS also reduced hind paw oedema at doses of 10 mg/kg and 25 mg/kg (p < 0.05; 42% and 58%, respectively) and pleurisy at doses of 10 mg/kg and 25 mg/kg (41% and 50%, respectively). In a chronic model, HFAS reduced inflammation by 46% and 58% at doses of 10 mg/kg and 25 mg/kg, respectively. Moreover, this fraction showed analgesic properties against the abdominal writhing in an acetic acid model (at doses of 5-25 mg/kg) with inhibitory rates of 24%, 54% and 48%. The HFAS also showed an increased latency time in the hot-plate (23% and 28%) and tail-flick tests (61% and 66%) for the 25 mg/kg and 50 mg/kg doses, respectively. These results suggest that HFAS has anti-inflammatory and analgesic properties.
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The aim of the present study was to analyse Taenia solium metacestode antigens that were derived from the unbound fraction of jacalin affinity chromatography and subsequent tert-octylphenoxy poly (oxyethylene) ethanol Triton X-114 (TX-114) partitioning in the diagnosis of human neurocysticercosis (NCC). Immunoassays were designed to detect T. solium-specific IgG antibodies by ELISA and immunoblot. Serum samples were collected from 132 individuals who were categorised as follows: 40 had NCC, 62 presented Taenia spp or other parasitic diseases and 30 were healthy individuals. The jacalin-unbound (J unbound ) fraction presented higher sensitivity and specificity rates than the jacalin-bound fraction and only this fraction was subjected to subsequent TX-114 partitioning, resulting in detergent (DJ unbound ) and aqueous (AJ unbound ) fractions. The ELISA sensitivity and specificity were 85% and 84.8% for J unbound , 92.5% and 93.5% for DJ unbound and 82.5% and 82.6% for AJ unbound . By immunoblot, the DJ unbound fraction showed 100% sensitivity and specificity and only serum samples from patients with NCC recognised the 50-70 kDa T. solium-specific components. We conclude that the DJ unbound fraction can serve as a useful tool for the differential immunodiagnosis of NCC by immunoblot.
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BACKGROUND Tapia's syndrome is an uncommon disease described in 1904 by Antonio Garcia Tapia, a Spanish otolaryngologist. It is characterized by concomitant paralysis of the hypoglossal (XIIth) and pneumogastric (Xth) nerves. Only 69 cases have been described in the literature. Typically, the reported patients presented with a history of orotracheal intubation. Common symptoms are dysphonia, tongue deviation toward the affected side, lingual motility disturbance, and swallowing difficulty. CASE PRESENTATION In the report, we describe three cases of Tapia's syndrome in three Caucasian patients who underwent surgery with general anesthesia. Two of these patients underwent neck abscess drainage, and the third had an open reduction of a shoulder fracture. The clinical symptoms of Tapia's syndrome appeared after extubation. All three of our patients recovered their lost function at 3 months after diagnosis. CONCLUSIONS We underline the importance of performing airway endoscopy and a specific program of swallowing rehabilitation for the proper management of Tapia's syndrome.
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Kuranishi's fundamental result (1962) associates to any compact complex manifold X&sub&0&/sub& a finite-dimensional analytic space which has to be thought of as a local moduli space of complex structures close to X&sub&0&/sub&. In this paper, we give an analogous statement for Levi-flat CR manifolds fibering properly over the circle by describing explicitely an infinite-dimensional Kuranishi type local moduli space of Levi-flat CR structures. We interpret this result in terms of Kodaira-Spencer deformation theory making clear the likenesses as well as the differences with the classical case. The article ends with applications and examples.
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Bonding of wood with glue dates back to ancient times but has increased enormously over the past decades. This 2 page report explains the proper way to glue wood.
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Xenopus laevis oocytes were used to assay for trans-acting factors shown previously to be involved in the liver-specific regulation of the vitellogenin genes in vitro. To this end, crude liver nuclear extracts obtained from adult estrogen-induced Xenopus females were fractionated by heparin-Sepharose chromatography using successive elutions with 0.1, 0.35, 0.6, and 1.0 M KCl. When these four fractions were injected into oocytes, only the 0.6-M KCl protein fraction significantly stimulated mRNA synthesis from the endogenous B class vitellogenin genes. This same fraction induced estrogen-dependent in vitro transcription from the vitellogenin B1 promoter, suggesting that it contains at least a minimal set of basal transcription factors as well as two positive factors essential for vitellogenin in vitro transcription, i.e. the NF-I-like liver factor B and the estrogen receptor (ER). The presence of these two latter factors was determined by footprinting and gel retardation assays, respectively. In contrast, injection of an expression vector carrying the sequence encoding the ER was unable to activate transcription from the oocyte chromosomal vitellogenin genes. This suggests that the ER alone cannot overcome tissue-specific barriers and that one or several additional liver components participate in mediating tissue-specific expression of the vitellogenin genes. In this respect, we present evidence that the oocyte germinal vesicles contain an NF-I-like activity different from that found in hepatocytes of adult frogs. This observation might explain the lack of vitellogenin gene activation in oocytes injected with the ER cDNA only.