960 resultados para Factor-b


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This is a secondary data-based study conducted to investigate whether gender is related to acceptance. Two Brazilian Medical Schools, Universities A and B, were studied. Their entrance exams (EE) were analysed and the number of candidates who took the EE was compared to the number of students admitted to the MS according to gender, in the period between 1995 and 2009. The same data from MS in the United States in 2011 was also evaluated. There was an increase in the percentage of female applicants but it did not correspond to the percentage of admitted students of the same gender. There was a trend of selecting men. At A, 39.3% of the applicants and 47% of the admitted students were men (OR = 1.37; CI95% = 1.24 – 1.51). In B, men represented 39.3% of the applicants and 65.4% of the admitted students (OR = 2.93; CI 95% = 2.76 – 3.11). This was not seen in US MS. The analysis of the EE suggests that the greater selection of men could be a product of EE format.

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Foot-and-mouth disease (FMD) is one of the most feared diseases of livestock worldwide. Vaccination has been a very effective weapon in controlling the disease, however a number of concerns with the current vaccine including the inability of approved diagnostic tests to reliably distinguish vaccinated from infected animals and the need for high containment facilities for vaccine production, have limited its use during outbreaks in countries previously free of the disease. A number of FMD vaccine candidates have been tested and a replication-defective human adenovirus type 5 (Ad5) vector containing the FMDV capsid (P1-2A) and 3C protease coding regions has been shown to completely protect pigs against challenge with the homologous virus (FMDV A12 and A24). An Ad5-P1-2A+3C vaccine for FMDV O1 Campos (Ad5-O1C), however, only induced a low FMDV-specific neutralizing antibody response in swine potency tests. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been successfully used to stimulate the immune response in vaccine formulations against a number of diseases, including HIV, hepatitis C and B. To attempt to improve the FMDV-specific immune response induced by Ad5-O1C, we inoculated swine with Ad5-O1C and an Ad5 vector containing the gene for porcine GM-CSF (pGM-CSF). However, in the conditions used in this trial, pGM-CSF did not improve the immune response to Ad5-O1C and adversely affected the level of protection of swine challenged with homologous FMDV.

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Many attempts have been made to establish the control of foodborne pathogens through Lactobacillus isolates and their metabolism products with success being obtained in several situations. The aim of this study was to investigate the antagonistic effect of eight Lactobacillusisolates, including L. caseisubsp. pseudoplantarum,L. plantarum, L. reuteri and L. delbrueckii subsp. delbrueckii, on the pathogenic Escherichia colistrain O157:H7. The inhibitory effect of pure cultures and two pooled cultures supernatants of Lactobacillus on the growth of pathogenic bacteria was evaluated by the spot agar method and by monitoring turbidity. Antimicrobial activity was confirmed for L. reuteri and L. delbrueckii subsp. delbrueckii and for a pool of lactic acid bacteria. The neutralized supernatant of the pool exerted a higher antimicrobial activity than that of the individual strains. Furthermore, D-lactic acid and acetic acid were produced during growth of the Lactobacillus isolates studied.

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Abstract: Infection with Escherichia coli (E. coli) is a common disease in poultry industry. The use of antibiotics to treat diseases is facing serious criticism and concerns. The medicinal plants may be effective alternatives because of their multiplex activities. The aim of this study was to investigate the effects of cinnamon extract on the levels of liver enzymes, tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa B (NF-κB) gene expressions in liver of broiler chickens infected with E. coli. Ninety Ross-308 broilers were divided into healthy or E. coli-infected groups, receiving normal or cinnamon extract (in concentrations of 100 or 200mg/kg of food) supplemented diets. E. coli suspension (108cfu) was injected subcutaneously after 12 days cinnamon administration. Seventy-two hours after E. coli injection, the blood samples were taken for biochemical analysis of liver enzymes in serum (spectrophotometrically), and liver tissue samples were obtained for detection of gene expression of inflammatory markers TNF-α and NF-κB, using real-time PCR. Infection with E. coli significantly increased the levels of TNF-α and NF-κB gene expressions as well as some liver enzymes including creatine-kinase (CK), lactate-dehydrogenase (LDH), alanine-transferase (ALT) and aspartate-transferase (AST) as compared with control group (P<0.05). Pre-administration of cinnamon extract in broilers diet (in both concentrations) significantly reduced the tissue levels of TNF-α and NF-κB gene expressions and enzymes CK and ALT in serum of broiler chickens inoculated with E. coli in comparison with E. coli group (P<0.05 and P<0.01). The levels of LDH and AST were significantly decreased only by 200mg/kg cinnamon extract in infected broilers. The level of alkaline-phosphatase (ALP) was not affected in any groups. Pre-administration of cinnamon extract in diets of broiler chickens inoculated with E. coli could significantly reduce the gene expression levels of pro-inflammatory mediators and liver enzymes activities, thereby protecting the liver against this pathologic condition.

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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

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Peripheral axonal regeneration was investigated in adult male mice of the C57BL/6J (C), BALB/cJ (B) and A/J (A) strains and in their F1 descendants using a predegenerated nerve transplantation model. Four types of transplants were performed: 1) isotransplants between animals of the C, B and A strains; 2) donors of the C strain and recipients of the C x B and C x A breeding; 3) donors of the B strain and recipients of the C x B breeding, and 4) donors of the A strain and recipients of the C x A breeding. Donors had the left sciatic nerve transected and two weeks later a segment of the distal stump was transplanted into the recipient. Four weeks after transplantation the regenerated nerves were used to determine the total number of regenerated myelinated fibers (TMF), diameter of myelinated fibers (FD) and myelin thickness (MT). The highest TMF values were obtained in the groups where C57BL/6J mice were the donors (C to F1 (C x B) = 4658 ± 304; C to F1 (C x A) = 3899 ± 198). Also, A/J grafts led to a significantly higher TMF (A to F1 (C x A) = 3933 ± 565). Additionally, isotransplant experiments showed that when the nerve is previously degenerated, C57BL/6J mice display the largest number of myelinated fibers (C to C = 3136 ± 287; B to B = 2759 ± 170, and A to A = 2835 ± 239). We also observed that when C57BL/6J was the graft donor, FD was the highest and MT did not differ significantly when compared with the other groups. These morphometric results reinforce the idea that Schwann cells and the nerve environment of C57BL/6J provide enough support to the regenerative process. In this respect, the present results support the hypothesis that the non-neuronal cells, mainly Schwann cells, present in the sciatic nerve of C57BL/6J mice are not the main limiting factor responsible for low axonal regeneration.

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The opportunistic bacterium Proteus mirabilis secretes a metalloprotease, ZapA, considered to be one of its virulence factors due to its IgA-degrading activity. However, the substrate specificity of this enzyme has not yet been fully characterized. In the present study we used fluorescent peptides derived from bioactive peptides and the oxidized ß-chain of insulin to determine the enzyme specificity. The bradykinin- and dynorphin-derived peptides were cleaved at the single bonds Phe-Ser and Phe-Leu, with catalytic efficiencies of 291 and 13 mM/s, respectively. Besides confirming already published cleavage sites, a novel cleavage site was determined for the ß-chain of insulin (Val-Asn). Both the natural and the recombinant enzyme displayed the same broad specificity, demonstrated by the presence of hydrophobic, hydrophilic, charged and uncharged amino acid residues at the scissile bonds. Native IgA, however, was resistant to hydrolysis by ZapA.

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Human plasma kallikrein, a serine proteinase, plays a key role in intrinsic blood clotting, in the kallikrein-kinin system, and in fibrinolysis. The proteolytic enzymes involved in these processes are usually controlled by specific inhibitors and may be influenced by several factors including glycosaminoglycans, as recently demonstrated by our group. The aim of the present study was to investigate the effect of glycosaminoglycans (30 to 250 µg/ml) on kallikrein activity on plasminogen and factor XII and on the inhibition of kallikrein by the plasma proteins C1-inhibitor and antithrombin. Almost all available glycosaminoglycans (heparin, heparan sulfate, bovine and tuna dermatan sulfate, chondroitin 4- and 6-sulfates) reduced (1.2 to 3.0 times) the catalytic efficiency of kallikrein (in a nanomolar range) on the hydrolysis of plasminogen (0.3 to 1.8 µM) and increased (1.9 to 7.7 times) the enzyme efficiency in factor XII (0.1 to 10 µM) activation. On the other hand, heparin, heparan sulfate, and bovine and tuna dermatan sulfate improved (1.2 to 3.4 times) kallikrein inhibition by antithrombin (1.4 µM), while chondroitin 4- and 6-sulfates reduced it (1.3 times). Heparin and heparan sulfate increased (1.4 times) the enzyme inhibition by the C1-inhibitor (150 nM).

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Tumor necrosis factor-alpha (TNF-alpha) is one of the most important proinflammatory cytokines which plays a central role in host defense and in the acute inflammatory response related to tissue injury. The major source of TNF-alpha are immune cells such as neutrophils and macrophages. We tested the hypothesis that pentoxifylline, a methylxanthine derivative, down-regulates proinflammatory cytokine expression during acute lung injury in rats. Male Wistar rats weighing 250 to 450 g were anesthetized ip with 50 mg/kg sodium thiopental and randomly divided into three groups: group 1 (N = 7): tidal volume (V T) = 7 ml/kg, respiratory rate (RR) = 50 breaths/min and normal saline infusion; group 2 (N = 7): V T = 42 ml/kg, RR = 9 breaths/min and normal saline infusion; group 3 (N = 7): V T = 42 ml/kg, RR = 9 breaths/min and pentoxifylline infusion. The animals were ventilated with an inspired oxygen fraction of 1.0, a positive end-expiratory pressure of 3 cmH2O, and normal saline or pentoxifylline injected into the left femoral vein. The mRNA of TNF-alpha rapidly increased in the lung tissue within 180 min of ventilation with a higher V T with normal saline infusion. The concentrations of inflammatory mediators were decreased in plasma and bronchoalveolar lavage (BAL) in the presence of higher V T with pentoxifylline infusion (TNF-alpha: plasma, 102.2 ± 90.9 and BAL, 118.2 ± 82.1; IL-1ß: plasma, 45.2 ± 42.7 and BAL, 50.2 ± 34.9, P < 0.05). We conclude that TNF-alpha produced by neutrophil influx may function as an alert signal in host defense to induce production of other inflammatory mediators.

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Because low tumor necrosis factor-alpha (TNF-alpha) production has been reported in malnourished children, in contrast with high production of TNF-alpha in experimental protein-energy malnutrition, we reevaluated the production of TNF-alpha in whole blood cultures from children with primary malnutrition free from infection, and in healthy sex- and age-matched controls. Mononuclear cells in blood diluted 1:5 in endotoxin-free medium released TNF-alpha for 24 h. Spontaneously released TNF-alpha levels (mean ± SEM), as measured by enzyme immunoassay in the supernatants of unstimulated 24-h cultures, were 10,941 ± 2,591 pg/ml in children with malnutrition (N = 11) and 533 ± 267 pg/ml in controls (N = 18) (P < 0.0001). TNF-alpha production was increased by stimulation with lipopolysaccharide (LPS), with maximal production of 67,341 ± 16,580 pg/ml TNF-alpha in malnourished children and 25,198 ± 2,493 pg/ml in controls (P = 0.002). In control subjects, LPS dose-dependently induced TNF-alpha production, with maximal responses obtained at 2000 ng/ml. In contrast, malnourished patients produced significantly more TNF-alpha with 0.02-200 ng/ml LPS, responded maximally at a 10-fold lower LPS concentration (200 ng/ml), and presented high-dose inhibition at 2000 ng/ml. TNF-alpha production a) was significantly influenced by LPS concentration in control subjects, but not in malnourished children, who responded strongly to very low LPS concentrations, and b) presented a significant, negative correlation (r = -0.703, P = 0.023) between spontaneous release and the LPS concentration that elicited maximal responses in malnourished patients. These findings indicate that malnourished children are not deficient in TNF-alpha production, and suggest that their cells are primed for increased TNF-alpha production.

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Exclusion of the transcription factor Max from the nucleus of retinal ganglion cells is an early, caspase-independent event of programmed cell death following damage to the optic axons. To test whether the loss of nuclear Max leads to a reduction in neuroprotection, we developed a procedure to overexpress Max protein in rat retinal tissue in vivo. A recombinant adeno-associated viral vector (rAAV) containing the max gene was constructed, and its efficiency was confirmed by transduction of HEK-293 cells. Retinal ganglion cells were accessed in vivo through intravitreal injections of the vector in rats. Overexpression of Max in ganglion cells was detected by immunohistochemistry at 2 weeks following rAAV injection. In retinal explants, the preparation of which causes damage to the optic axons, Max immunoreactivity was increased after 30 h in vitro, and correlated with the preservation of a healthy morphology in ganglion cells. The data show that the rAAV vector efficiently expresses Max in mammalian retinal ganglion cells, and support the hypothesis that the Max protein plays a protective role for retinal neurons.

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The biologic basis of the negative prognosis of plasmablastic myeloma is not fully understood. To determine whether histologically aggressive multiple myeloma (MM) is associated with a more angiogenic marrow environment, bone marrow samples from 50 recently diagnosed MM patients were evaluated. Twelve percent (6/50) of patients presented plasmablastic MM, and this feature correlated with moderate/strong intensity of vascular endothelial growth factor staining of plasma cells (P = 0.036). Although plasmablastic MM was not associated with increasing of microvessel density, this new evidence of increased expression of vascular endothelial growth factor on plasmablasts suggests that the adverse prognosis conferred by plasmablastic disease may be due, at least in part, to secretion of this angiogenic cytokine, also suggesting that the subset of MM patients with plasmablastic features may derive particular benefit from antiangiogenic therapies.

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Transitional cell carcinoma (TCC) of the urothelium is often multifocal and subsequent tumors may occur anywhere in the urinary tract after the treatment of a primary carcinoma. Patients initially presenting a bladder cancer are at significant risk of developing metachronous tumors in the upper urinary tract (UUT). We evaluated the prognostic factors of primary invasive bladder cancer that may predict a metachronous UUT TCC after radical cystectomy. The records of 476 patients who underwent radical cystectomy for primary invasive bladder TCC from 1989 to 2001 were reviewed retrospectively. The prognostic factors of UUT TCC were determined by multivariate analysis using the COX proportional hazards regression model. Kaplan-Meier analysis was also used to assess the variable incidence of UUT TCC according to different risk factors. Twenty-two patients (4.6%). developed metachronous UUT TCC. Multiplicity, prostatic urethral involvement by the bladder cancer and the associated carcinoma in situ (CIS) were significant and independent factors affecting the occurrence of metachronous UUT TCC (P = 0.0425, 0.0082, and 0.0006, respectively). These results were supported, to some extent, by analysis of the UUT TCC disease-free rate by the Kaplan-Meier method, whereby patients with prostatic urethral involvement or with associated CIS demonstrated a significantly lower metachronous UUT TCC disease-free rate than patients without prostatic urethral involvement or without associated CIS (log-rank test, P = 0.0116 and 0.0075, respectively). Multiple tumors, prostatic urethral involvement and associated CIS were risk factors for metachronous UUT TCC, a conclusion that may be useful for designing follow-up strategies for primary invasive bladder cancer after radical cystectomy.

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Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50% of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.

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Genotype E of hepatitis B virus (HBV) has not been described in Brazil and is found mainly in Africa. Genotype A is the most prevalent in Brazil, and genotypes B, C, D, and F have already been reported. We report here an HBV genotype E-infected patient and some characterization of surface (S) protein, DNA polymerase (P) and precore/core (preC/C) coding regions based on the viral genome. The patient is a 31-year-old black man with chronic hepatitis B who was born and raised in Angola. He has been followed by a hepatologist in São Paulo, Brazil, since November 2003, and he is a frequent traveler to Latin America, Africa, and Europe. In 2003, he was diagnosed with HBV infection and started treatment with lamivudine with the later addition of adefovir dipivoxil. No known risk factor was identified. Serologically, he is HBsAg and anti-HBe positive, but HBeAg and anti-HBs negative. DNA sequence analysis of the S/P region confirmed that this patient is infected with genotype E, subtype ayw4. The preC/C region showed G1896A and G1899A mutations but no mutations in the basal core promoter. Nucleotide substitutions common in genotype E were also observed (C1772, T1858 and A1757). Although this is not an autochthonous case and there is no evidence of further spread, the description of this case in Brazil highlights the current risk of viral genotypes spreading with unprecedented speed due to constant travel around the world.