2,158 research outputs found

    NALP1 is a transcriptional target for cAMP-response-element-binding protein (CREB) in myeloid leukaemia cells

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    NALP1 (also called DEFCAP, NAC, CARD7) has been shown to play a central role in the activation of inflammatory caspases and processing of pro-IL1β (pro-interleukin-1β). Previous studies showed that NALP1 is highly expressed in peripheral blood mononuclear cells. In the present study, we report that expression of NALP1 is absent from CD34+ haematopoietic blast cells, and its levels are upregulated upon differentiation of CD34+ cells into granulocytes and to a lesser extent into monocytes. In peripheral blood cells, the highest levels of NALP1 were observed in CD3+ (T-lymphocytes), CD15+ (granulocytes) and CD14+ (monocytes) cell populations. Notably, the expression of NALP1 was significantly increased in the bone marrow blast cell population of some patients with acute leukaemia, but not among tissue samples from thyroid and renal cancer. A search for consensus sites within the NALP1 promoter revealed a sequence for CREB (cAMP-response-element-binding protein) that was required for transcriptional activity. Moreover, treatment of TF1 myeloid leukaemia cells with protein kinase C and protein kinase A activators induced CREB phosphorylation and upregulated the mRNA and protein levels of NALP1. Conversely, ectopic expression of a dominant negative form of CREB in TF1 cells blocked the transcriptional activity of the NALP1 promoter and significantly reduced the expression of NALP1. Thus NALP1 is transcriptionally regulated by CREB in myeloid cells, a mechanism that may contribute to modulate the response of these cells to pro-inflammatory stimuli

    Production, immobilization and synthesis of pharmacological derivatives of lipase B from Candida antarctica in Pichia pastoris

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    Lipase B from Candida antarctica (CALB) is widely used because of its excellent enantioselectivity. Producing this recombinant lipase in Pichia pastoris has advantages since it can be cultured in simple media and can reach high cell densities. This capability is especially important when using a constitutive promoter for lipase production, as here. The PPGK promoter is similar to the well-known PGAP promoter and also circumvents the need for inducing production with methanol, which is a hazard when used on a large scale and would increase the downstream production costs, which could be prohibitive for pharmaceutical products. This study tested two main fermentation strategies: continuous and fed-batch. In both cultures, different specific growth rates occurred (0.05, 0.10, 0.15 and 0.18h–1), and process parameters (qP, qS, YX/S, YP/X, YP/S) were evaluated in order to properly compare them. The highest specific production rate achieved with a continuous culture was 57.71 U/gX.h with µ=0.15 h–1 and 16 U/gX.h with µ=0.14 h–1 for a fed-batch culture. Productivity decreased dramatically near the µmax (0.18 h–1) for P. pastoris (57.6% lower). The best strategy for production was calculated over a three-month period. In both cases, the enzyme is secreted to the supernatant and purification is needed to ensure that only LIPB participates in further reactions. The immobilization process is ideal because purification and concentration is achieved in only one step, reusability is made possible, and in certain cases, stability and efficiency are boosted. Hydrophobic core-shell polymeric supports synthesized by a combined suspension and emulsion polymerization process have shown good potential for lipase immobilization procedures and were used in this study, compared to traditional supports such as Accurel, in order to determine their efficiency. After the enzyme was immobilized, the reactions included the resolution of (±)-1,3,5-O-benzyl-myo-inositol (DL-1) via acylation using vinyl acetate in hexane, and resolution of (±)-1,2-O- isopropylidene-3,6-di-O-benzyl-myo-inositol (DL-2) via acylation using vinyl acetate (solvent-free system). The support used directly affected the reaction, but trends were observed. In general, the recombinant lipase produced (LIPB) had higher resolutions than the commercial lipase (CALB, Novozym 435). In the resolution of DL-1 and DL-2 via transesterification (using different media), LIPB immobilized in Accurel or PS-co-DVB/PS-co-DVB showed more activity per enzyme molecule than CALB immobilized in similar supports, while when immobilized in PMMA-co-DVB/ PMMA-co-DVB the activities of the two enzymes were similar. The recombinant LIPB immobilized on PS-co-DVB proved to be the most efficient in the enantioselective resolution of both racemic derivatives, DL-1 and DL-2. The productivity for DL-2 resolution was 50% higher than the commercial Novozym 435, and the new derivative was operationally more stable than Novozym 435. The products obtained had a high level of purity (ee of 99% for both derivatives). Both products of the enantio-selective reaction, L-2 and L-5, obtained from the racemic derivatives (DL-1 and DL-2, respectively), are intermediates from different pharmacological pathways involved in the synthesis of building blocks for drugs that inhibit the etiological agent of Chagas disease, Trypanosoma cruzi

    The Brazilian Network for HIV-1 Genotyping External Quality Control Assurance Programme

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    The Brazilian network for genotyping is composed of 21 laboratories that perform and analyze genotyping tests for all HIV-infected patients within the public system, performing approximately 25,000 tests per year. We assessed the interlaboratory and intralaboratory reproducibility of genotyping systems by creating and implementing a local external quality control evaluation. Plasma samples from HIV-1-infected individuals (with low and intermediate viral loads) or RNA viral constructs with specific mutations were used. This evaluation included analyses of sensitivity and specificity of the tests based on qualitative and quantitative criteria, which scored laboratory performance on a 100-point system. Five evaluations were performed from 2003 to 2008, with 64% of laboratories scoring over 80 points in 2003, 81% doing so in 2005, 56% in 2006, 91% in 2007, and 90% in 2008 (Kruskal-Wallis, p = 0.003). Increased performance was aided by retraining laboratories that had specific deficiencies. The results emphasize the importance of investing in laboratory training and interpretation of DNA sequencing results, especially in developing countries where public (or scarce) resources are used to manage the AIDS epidemic

    Influence of Malignant Pleural Fluid from Lung Adenocarcinoma Patients on Neutrophil Response

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    Malignant pleural effusion (MPE) is a common severe complication of advanced lung adenocarcinoma (LAC). Neutrophils, an essential component of tumor infiltrates, contribute to tumor progression and their counts in MPE have been associated with worse outcome in LAC. This study aimed to evaluate phenotypical and functional changes of neutrophils induced by MPE to determine the influence of MPE immunomodulatory factors in neutrophil response and to find a possible association between neutrophil functions and clinical outcomes. Pleural fluid samples were collected from 47 LAC and 25 heart failure (HF) patients. We measured neutrophil degranulation products by ELISA, oxidative burst capacity and apoptosis by flow cytometry, and NETosis by fluorescence. The concentration of degranulation products was higher in MPE-LAC than in PE-HF. Functionally, neutrophils cultured with MPE-LAC had enhanced survival and neutrophil extracellular trap (NET) formation but had reduced oxidative burst capacity. In MPE, NETosis was positively associated with MMP-9, P-selectin, and sPD-L1 and clinically related to a worse outcome. This is the first study associating NETs with a worse outcome in MPE. Neutrophils likely contribute to tumor progression through the release of NETs, suggesting that they are a potential therapeutic target in LAC

    Clinical and ultrasound thyroid nodule characteristics and their association with cytological and histopathological outcomes: A retrospective multicenter study in high-resolution thyroid nodule clinics

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    Introduction: Thyroid nodules are a common finding. A high-resolution thyroid nodule clinic (HR-TNC) condenses all tests required for the evaluation of thyroid nodules into a single appointment. We aimed to evaluate the clinical outcomes at HR-TNCs. Design and Methods: A retrospective cross-sectional multicenter study including data from four HR-TNCs in Spain. We evaluated fine-needle aspiration (FNA) indications and the association between clinical and ultrasound characteristics with cytological and histopathological outcomes. Results: A total of 2809 thyroid nodules were included; FNA was performed in 82.1%. Thyroid nodules that underwent FNA were more likely larger, isoechoic, with microcalcifications, and in younger subjects. The rate of nondiagnostic FNA was 4.3%. A solid component, irregular margins or microcalcifications, significantly increased the odds of Bethesda IV-V-VI (vs. Bethesda II). Irregular margins and a solid component were independently associated with increased odds of malignancy. Thyroid nodules <20 mm and ≥20–<40 mm had a 6.5-fold and 3.3-fold increased risk for malignancy respectively in comparison with those ≥40 mm. Conclusion: In this large multicenter study, we found that the presence of a solid component and irregular margins are factors independently related to malignancy in thyroid nodules. Since nodule size ≥40 mm was associated with the lowest odds of malignancy, this cut-off should not be a factor leading to indicate thyroid surgery. HR-TNCs were associated with a low rate of nondiagnostic FNA

    Gastroduodenal injury after radioembolization of hepatic tumors

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    Radioembolization is a new tool for the treatment of hepatic tumors that consists in the injection of biocompatible microspheres carrying radioisotopes into the hepatic artery or its branches. METHODS: We have performed radioembolization in 78 patients with hepatic tumors using resin-based microspheres loaded with yttrium-90. All patients were previously evaluated to minimize the risk of hazardous irradiation to nontarget organs and to obtain the data needed for dose calculation. RESULTS: We report a complication found in three cases (3.8%) that consists of abdominal pain resulting from gastroduodenal lesions and that had a chronic, insidious course. Microscopically, microspheres were detected in the specimens obtained from all affected gastric areas. Since these gastroduodenal lesions do not appear when nonradiating microspheres are injected in animals, lesions are likely to be due to radiation and not to an ischemic effect of vascular occlusion by spheres. CONCLUSIONS: We believe that a pretreatment evaluation that includes a more thorough scrutiny of the hepatic vascularization in search of small collaterals connecting to the gastroduodenal tract can help prevent this awkward complicatio

    Further Characterization of the Electrogenicity and pH Sensitivity of the Human Organic Anion-Transporting Polypeptides OATP1B1 and OATP1B3

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    Organic anion-transporting polypeptides (OATPs) are involved in the liver uptake of many endogenous and xenobiotic compounds, such as bile acids and drugs, respectively. Using Xenopus laevis oocytes and Chinese hamster ovary (CHO) cells expressing rat Oatp1a1, human OATP1B1, or OATP1B3, the sensitivity of these transporters to extracellular/intracellular pH (pHo/pHi) and changes in plasma membrane potential (ΔΨ) was investigated. In X. laevis oocytes, nonspecific plasma membrane permeability increased only at pHo below 4.5. Above this value, both using oocytes and CHO cells, extracellular acidification affected differently the specific transport of taurocholic acid (TCA) and estradiol 17β-d-glucuronide (E217βG) by Oatp1a1 (stimulation), OATP1B1 (inhibition), and OATP1B3 (stimulation). Changes in substrate uptake in the presence of valinomycin (K+-ionophore), carbonyl cyanide 3-chlorophenylhydrazone and nigericin (protonophores), and amiloride (Na+/H+-inhibitor) and cation replacement in the medium were studied with fluorescent probes for measuring substrate uptake (cholylglycyl amidofluorescein) and changes in pHi (SNARF-4F) and ΔΨ [DilC1(5)]. The results suggest that activity of these three carriers is sodium/potassium-independent and affected differently by changes in pHo and ΔΨ: Oatp1a1 was confirmed to be an electroneutral anion exchanger, whereas the function of both OATP1B1 and OATP1B3 was markedly affected by the magnitude of ΔΨ. Moreover, electrophysiological measurements revealed the existence of a net anion influx associated to OATP1B1/OATP1B3-mediated transport of TCA, E217βG, and estrone-3-sulfate. Furthermore, a leakage of Na+ through OATP1B1 and OATP1B3, which is not coupled to substrate transport, was found. In conclusion, these results suggest that OATP1B1 and OATP1B3 are electrogenic transporters whose activity may be strongly affected under circumstances of displacement of local pH

    Evaluation of different bowel preparations for small bowel capsule endoscopy: a prospective, randomized, controlled study

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    To obtain an adequate view of the whole small intestine during capsule endoscopy (CE) a clear liquid diet and overnight fasting is recommended. However, intestinal content can hamper vision in spite of these measures. Our aim was to evaluate tolerance and degree of intestinal cleanliness during CE following three types of bowel preparation. PATIENTS AND METHODS: This was a prospective, multicenter, randomized, controlled study. Two-hundred ninety-one patients underwent one of the following preparations: 4 L of clear liquids (CL) (group A; 92 patients); 90 mL of aqueous sodium phosphate (group B; 89 patients); or 4 L of a polyethylene glycol electrolyte solution (group C; 92 patients). The degree of cleanliness of the small bowel was classified by blinded examiners according to four categories (excellent, good, fair or poor). The degree of patient satisfaction, gastric and small bowel transit times, and diagnostic yield were measured. RESULTS: The degree of cleanliness did not differ significantly between the groups (P = 0.496). Interobserver concordance was fair (k = 0.38). No significant differences were detected between the diagnostic yields of the CE (P = 0.601). Gastric transit time was 35.7 +/- 3.7 min (group A), 46.1 +/- 8.6 min (group B) and 34.6 +/- 5.0 min (group C) (P = 0.417). Small-intestinal transit time was 276.9 +/- 10.7 min (group A), 249.7 +/- 13.1 min (group B) and 245.6 +/- 11.6 min (group C) (P = 0.120). CL was the best tolerated preparation. Compliance with the bowel preparation regimen was lowest in group C (P = 0.008). CONCLUSIONS: A clear liquid diet and overnight fasting is sufficient to achieve an adequate level of cleanliness and is better tolerated by patients than other forms of preparation
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