935 resultados para Mucosal Immunity
Resumo:
To describe a new suture technique for laryngeal microsurgery and to test its applicability in human cadaver larynges. The new technique was experimentally tested in freshly excised human larynges fixed to a larynx holder appropriate for the simulation of laryngeal microsurgery. A mucosal flap was created in the vocal fold for the fabrication of a pocket for subepithelial fat implantation, and the wound edges were then brought together and sutured using the proposed technique. The time necessary for suture was measured with a stopwatch for five successive sutures performed by one of the surgeons. The presence or absence of mucosal rupture was determined for five sutures performed by two surgeons, for a total of 10 sutures. The sutures were performed without the help of an assistant, with no laceration of the mucosa being observed in any of the attempts, and within a relatively short period of time even without previous training. The sutures performed permitted the implanted fat to remain stable under the mucosal flap. Conclusions: the new suture technique is an easy procedure, which can be performed by a single surgeon under microscopic vision, with a low risk of tissue rupture. The technique does not markedly prolong the duration of surgery and a single suture thread can be used for the fabrication of more than one stitch.
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Two longitudinal experiments involving Angora goats challenged with either bovine or ovine strains of Mycobacterium avium subspecies paratuberculosis (Map) have been conducted over a period of 54 and 35 months, respectively. Blood samples for the interferon-gamma (IFN-gamma) test and the absorbed ELISA and faecal samples for bacteriological culture were taken pre-challenge and monthly post-challenge. Persistent shedding, IFN-gamma production, seroconversion and clinical disease occurred earlier with the bovine Map gut mucosal tissue challenge inoculum than with cultured bacteria. The IFN-gamma responses of the gut mucosal tissue and bacterial challenge groups were substantially and consistently higher than those of the control group. The in vivo and cultured cattle strains were much more pathogenic for goats than the sheep strains with persistent faecal shedding, seroconversion and clinical disease occurring in the majority of bovine Map challenged goats. With the ovine Map, 3 goats developed persistent antibody responses but only one of these goats developed persistent faecal shedding and clinical disease. However, there was no significant difference between the IFN-gamma responses of the tissue challenged, bacterial challenged and control groups. Compared with sheep, the ELISA appeared to have higher sensitivity and the IFN-gamma test lower specificity. (C) 2005 Elsevier B.V. All rights reserved.
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Lung disease during active human visceral leishmaniasis is frequently reported. As such, studies have associated pulmonary symptoms to interstitial pneumonitis with a mononuclear infiltrate. However, the immune response in this condition has never been described before. The aim of this study was to determine the immunophenotypic pattern and cytokine profile of lung involvement (IPL) in human visceral leishmaniasis. Quantitative methods of analysis were performed using immunohistochemistry, and were compared with a control group of normal lung. Interstitial macrophages and cd8 cells were increased in IPL, and IL-4 as well as TNF-alpha displayed increased expression when compared to the control group. This inflammatory process with a Th2 pattern, as suggested by increased IL-4 and low IFN-gamma expression, is consistent with the immune response in other organs of visceral leishmaniasis. The microenvironment of the immune response in this condition is associated with lung disease in patients with interstitial pneumonitis related to visceral leishmaniasis, increasing the chance of bacterial infection.
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Comorbidity from tegumentary leishmaniasis and AIDS is poorly characterized. To describe a series of patients coinfected with Leishmania and human immunodeficiency virus (HIV). Clinical records from patients were analysed by demographic data, clinical manifestations, diagnoses, treatments and outcomes. Fifteen cases of AIDS/tegumentary leishmaniasis were found. The diagnosis of leishmaniasis was confirmed by the detection of Leishmania amastigotes or antigens from the cutaneous or mucosal lesions. The mean CD4+ T-cell count was 84 cells mm(-3) (range 8-258) and all patients were classified as having AIDS according to the Centers for Disease Control and Prevention. A wide range of manifestations was found, varying from a single ulcer to multiple and polymorphic lesions. Mucosal lesions were present in 80% and cutaneous lesions in 73% of patients (53% with mucocutaneous form), disseminated lesions in 60% and genital lesions in 27% of patients. All patients received anti-Leishmania therapy and 53% showed relapses. Sixty-seven per cent received highly active antiretroviral therapy but showed no difference in outcomes and relapses compared with those not using medication. Forty per cent died during the study period. In these patients, the anti-Leishmania antibody and Montenegro skin test were useful in the diagnosis of leishmaniasis, probably because leishmaniasis preceded immunosuppression due to HIV infection. Clinical manifestations of tegumentary leishmaniasis in HIV-infected patients are diverse. Our data emphasize possible unusual manifestations of this disease in HIV-infected patients, particularly in severely immunosuppressed cases (< 200 CD4+ cells mm(-3)).
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Precis Women with recurrent vulvovaginal candidiasis (RVC) due to a polymorphism in codon 54 of the MBL2 gene respond better to fluconazole maintenance therapy than do women with other underlying causes. Objective To explain differences in response rates to maintenance therapy with fluconazole in women suffering from RVC by evaluating associations with a polymorphism in the gene coding for mannose-binding lectin (MBL). Design Follow-up study, neted case-control group. Setting Women attending vulvoginitis clinic for RVC. Population Women participating in a multicentric study in Belgium with a degressive dose of fluconazole for RVC (the ReCiDiF trial) were divided into good responders, intermediate responders and nonresponders according to the number of relapses they experienced during therapy. From 109 of these women with adequate follow-up data, vaginal lavage with 2 ml of saline were performed at the moment of a proven acute attack at inclusion in the study, before maintenance treatment was started. A buccal swab was obtained from 55 age-matched women without a history of Candida infections, serving as a control group. Methods Extracted DNA from buccal or vaginal cells was tested for codon 54 MBL2 gene polymorphism by polymerase chain reaction and endonuclease digestion. Main outcome measures Frequency of MBL2 condon 54 allele B in women with optimal or poor response to maintenance therapy in composition with controls. Results Women (n = 109) suffering from RVC were more likely to carry the variant MBL2 codon 54 allele B than control women (20 versus 6.6%, OR 3.4 [95% CI 1.3-8.2], P = 0.01). B alleles were present in 25% of the 36 women not suffering from any recurrence during the maintenance therapy with decreasing doses of fluconazole (OR 4.9 [95% CI 1.9-12.5], P = 0.0007 versus controls), in 20% of the 43 women with sporadic recurrences (OR 3.6 [95% CI 1.4-9.2], P = 0.007 versus controls) and in 15% of the 30 women who had to interrupt the treatment regimen due to frequent relapses (P = 0.097 versus controls). Conclusions The MBL2 codon 54 gene polymorphism is more frequent in Belgian women suffering from RVC than in controls. The presence of the B allele is associated with a superior response to fluconazole maintenance therapy as compared with RVC patients without this polymorphism. We conclude that RVC due to deficient MBL production is more easily helped with antifungal medication than is RVC due to some other mechanism.
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Amongst the infectious diseases that threaten equine health, herpesviral infections remain a world wide cause of serious morbidity and mortality. Equine herpesvirus-1 infection is the most important pathogen, causing an array of disorders including epidemic respiratory disease abortion, neonatal foal death, myeloencephalopathy and chorioretinopathy. Despite intense scientific investigation, extensive use of vaccination, and established codes of practice for control of disease outbreaks, infection and disease remain common. While equine herpesvirus-1 infection remains a daunting challenge for immunoprophylaxis, many critical advances in equine immunology have resulted in studies of this virus, particularly related to MHC-restricted cytotoxicity in the horse. A workshop was convened in San Gimignano, Tuscany, Italy in June 2004, to bring together clinical and basic researchers in the field of equine herpesvirus-1 study to discuss the latest advances and future prospects for improving our under-standing of these diseases, and equine immunity to herpesviral infection. This report highlights the new information that was the focus of this workshop, and is intended to summarize this material and identify the critical questions in the field. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
Infections caused by the yeast Candida albicans represent an increasing threat to debilitated and immunosuppressed patients, and neutropenia is an important risk factor. Monoclonal antibody depletion of neutrophils in mice was used to study the role of these cells in host resistance. Ablation of neutrophils increased susceptibility to both systemic and vaginal challenge. The fungal burden in the kidney increased threefold on day 1, and 100-fold on day 4, and infection was associated with extensive tissue destruction. However, a striking feature of the disseminated disease in neutrophil-depleted animals was the altered pattern of organ involvement. The brain, which is one of the primary target organs in normal mice, was little affected. There was a threefold increase in the number of organisms recovered from the brains of neutrophil-depleted mice on day 4 after infection, but detectable abscesses were rare. In contrast, the heart, which in normal mice shows only minor lesions, developed severe tissue damage following neutrophil depletion. Mice deficient in C5 demonstrated both qualitative and quantitative increases in the severity of infection after neutrophil depletion when compared with C5-sufficient strains. The results are interpreted as reflecting organ-specific differences in the mechanisms of host resistance.
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Background Obesity is related to a higher rate of infections and some types of cancer. Here we analyzed the impact of obesity and weight loss induced by Roux-en-Y gastric bypass (RYGB) on immunological parameters, i.e., cytokine productions and natural killer cell function. Methods We analyzed 28 morbidly obese patients before and 6 months after RYGB. Biochemical parameters were analyzed in plasma. The percent of natural killer (NK) cells, their cytotoxicity, and the production of cytokines by peripheral blood mononuclear cells were analyzed. The percent of NK cells was determined by flow cytometry and cytokine production determined by enzyme-linked immunosorbent assay. NK cytotoxicity was determined by the lactate dehydrogenase release assay. Results The weight loss 6 months following surgery was 35.3 +/- 4.5 kg. RYGB also improves biochemical parameters. No significant difference was found in the percent of NK cells after surgery. We found an increase in the production of interferon-gamma, interleukin (IL)-12 and IL-18, but not in IL-2, 6 months after RYGB. Cytotoxic activity of NK cells was significantly enhanced 6 months after RYGB [17.1 +/- 14.7% before RYGB vs 51.8 +/- 11.3% at 6 months after, at 40: 1 effector to target cell ratio; p<0.001]. We observed significant post-surgical improvement in the cytotoxic activity curve in 22 out of 28 patients (78.6%), irrespective of the target to effector cell ratio. Conclusions The weight loss induced by RYGB modifies the production of cytokines related with NK cell function and improves its activity.
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Prophylactic vaccines for genital human papillomavirus (HPV) infection have been shown to be feasible in animal models, and suitable vaccine material based on virus-like particles can be produced in bulk at reasonable cost. Initiation of phase III clinical trials will follow definition of trial outcome measures through further epidemiological studies, and development-of assays of host protective immunity. Vaccines could in principle eliminate HPV-related disease, as the human race is the only natural host for the relevant papillomaviruses (PVs). Therapeutic vaccines for genital HPV infection are also possible, but have not yet been demonstrated as feasible in practice because the choice of vaccine antigens is difficult, the method of their optimal delivery is uncertain, and the nature of the relevant antiviral immunity is unknown. PV species specificity will require trials to be conducted in man, which will slow definition of an ideal vaccine.
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Purpose: Most groups have reported disappointing results with autoaugmentation or detrusor myectomy for low capacity/compliance neuropathic bladders. Failure may be due to an ischemic diverticulum or mucosal shrinkage. We investigated whether a Silimed (R) silicone balloon placed in the bladder after autoaugmentation could prevent these problems, improving surgical results. Materials and Methods: We compared the results of standard bladder autoaugmentation in 12 children (group 1) with those in 10 (group 2) who underwent the same surgery using a bladder conformer. The conformer was a silicone balloon filled with saline that remained in the bladder for 2 weeks. All patients had a neuropathic bladder with poor capacity and compliance, resulting in urinary leakage between catheterizations. Preoperative and postoperative evaluation included a voiding diary, ultrasound, voiding cystourethrogram and urodynamics. Results: In group 1 only 1 patient became dry, 4 had little improvement in continence, 4 remained unchanged and 3 became worse. In group 2, 6 patients (60%) become continent without medication, 2 (20%) become continent with oxybutynin and 2 remained unchanged. Bladder capacity and compliance did not change significantly in group 1. However, in group 2 capacity changed from a mean of 140 to 240 ml and mean +/- SD compliance increased from 15.6 +/- 16.8 to 34.3 +/- 22.8 ml/cm H(2)O (p = 0.02). Conclusions: The inflatable balloon improved our long-term results of bladder auto-augmentation. A larger series may be necessary to confirm procedure efficacy and safety.
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Purpose: Bacillus Calmette-Guerin (BCG) continues to be employed as the most effective immunotherapy against superficial bladder cancer. We have developed an rBCG-S1PT strain that induces a stronger cellular immune response than BCG. This preclinical study was designed to test the potential of rBCG-S1PT as an immunotherapeutic agent for intravesical bladder cancer therapy. Materials and methods: A tumor was induced in C57BL/6 mice after chemical cauterization of the bladder and inoculation of the tumor cell line MB49. Next, mice were treated by intravesical instillation with BCG, rBCG-S1PT, or PBS once a week for 4 weeks. After 35 days, the bladders were removed and weighed, Th1 (IL-2, IL-12, INOS, INF-gamma, TNF-alpha), and Th2 (IL-5, IL-6, IL-10, TGF-beta) cytokine mRNA responses in individual mice bladders were measured by quantitative real time PCR, and the viability of MB49 cells in 18-hour coculture with splenocytes from treated mice was assessed. In an equivalent experiment, animals were observed for 60 days to quantify their survival. Results: Both BCG and rBCG-S1PT immunotherapy resulted in bladder weight reduction, and rBCG-S1PT increased survival time compared with the control group. There were increases in TNF-alpha in the BCG treated group, as well as increases in TNF-alpha and IL-10 mRNA in the rBCG-S1PT group. The viability of MB49 cells cocultured with splenocytes from rBCG-S1PT-treated mice was lower than in both the BCG and control groups. Conclusions: rBCG-S1PT therapy improved outcomes and lengthened survival times. These results indicate that rBCG could serve as a useful substitute for wild-type BCG. (C) 2010 Elsevier Inc. All rights reserved.
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IRI is closely related to sepsis in ITx setting. Complete understanding of the mechanisms involved in IRI development may improve outcomes. Ortothopic ITx without immunosuppression was performed in order to characterize IRI-associated mucosal damage. Twenty pigs underwent ITx. Two groups were assigned to different CI times: G1: 90 min and, G2: 180 min. Euro-Collins was used as preservation solution. Jejunal fragments were collected at donor laparotomy, 30 min, and 3 days after reperfusion. IRI assessment involved: histopathologic analysis, quantification of MPO-positive cells through immunohistochemical studies, quantification of epithelial apoptotic cells using TUNEL staining, and quantification of IL-6, ET-1, Bak, and Bcl-XL genes expression by RT-PCR. Neutrophilic infiltration increased in a similar fashion in both groups, but lasted longer in G2. Apoptosis detected by TUNEL staining increased and anti-apoptotic gene Bcl-XL expression decreased significantly in G1, 3 days after surgery. Endothelin-1 and IL-6 genes expression increased 30 min after the procedure and returned to baseline 3 days after surgery. In conclusion, IL-6 and ET-1 are involved precociously in the development of intestinal IRI. Apoptosis was more frequently detected in G1 grafts by TUNEL-staining and by RT-PCR.
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Background. Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. Among T. cruzi-infected individuals, only a subgroup develops severe chronic Chagas cardiomyopathy (CCC); the majority remain asymptomatic. T. cruzi displays numerous ligands for the Toll-like receptors (TLRs), which are an important component of innate immunity that lead to the transcription of proinflammatory cytokines by nuclear factor-kappa B. Because proinflammatory cytokines play an important role in CCC, we hypothesized that single-nucleotide polymorphisms (SNPs) in the genes that encode proteins in the TLR pathway could explain differential susceptibility to CCC among T. cruzi-infected individuals. Methods. For 169 patients with CCC and 76 T. cruzi-infected, asymptomatic individuals, we analyzed SNPs by use of polymerase chain reaction-restriction fragment length polymorphism analysis for the genes TLR1, TLR2, TLR4, TLR5, TLR9, and MAL/TIRAP, which encodes an adaptor protein. Results. Heterozygous carriers of the MAL/TIRAP variant S180L were more prevalent in the asymptomatic group (24 [32%] of 76 subjects) than in the CCC group (21 [12%] of 169) (chi(2) = 12.6; P = .0004 [adjusted P (P(c)) = .0084]; odds ratio [OR], 0.31 [95% confidence interval {CI}, 0.16-0.60]). Subgroup analysis showed a stronger association when asymptomatic patients were compared with patients who had severe CCC (i.e., patients with left-ventricular ejection fraction <= 40%) (chi(2) = 11.3; P = .0008 [P(c) = .017]; OR, 0.22 [95% CI, 0.09-0.56]) than when asymptomatic patients were compared with patients who had mild CCC (i.e., patients with left-ventricular ejection fraction >40%) (chi(2) = 7.7; P = .005 [P(c) = .11]; OR, 0.33 [95% CI, 0.15-0.73]). Conclusion. T. cruzi-infected individuals who are heterozygous for the MAL/TIRAP S180L variant that leads to a decrease in signal transduction upon ligation of TLR2 or TLR4 to their respective ligand may have a lower risk of developing CCC.
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Sm14 and paramyosin are two major Schistosoma mansoni vaccine candidate antigens. Recently, we have identified Sm14 and paramyosin epitopes that are recognized by T cells of resistant individuals living in endemic areas for schistosomiasis. Herein, mice were immunized with these peptides separately or in association in order to evaluate their vaccine potential. Immunization of mice with Sm14 peptides alone or mixed with paramyosin peptides was able to induce 26%-36.7% or 28%-29.2% of worm burden reduction, 67% or 46% of intestinal eggs reduction and also 54%-61% or 43%-52% of liver pathology reduction, respectively. Protection was associated with a Th1 type of immune response induced by Sm14 peptide immunization. In contrast, paramyosin peptide vaccination did not engender protective immunity or liver pathology reduction and immunization was associated with a Th2 type of immune response. (C) 2008 Elsevier B.V. All rights reserved.
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Sepsis syndrome is caused by inappropriate immune activation due to bacteria and bacterial components released during infection. This syndrome is the leading cause of death in intensive care units. Specialized B-lymphocytes located in the peritoneal and pleural cavities are known as B-1 cells. These cells produce IgM and IL-10, both of which are potent regulators of cell-mediated immunity. It has been suggested that B-1 cells modulate the systemic inflammatory response in sepsis. In this study, we conducted in vitro and in vivo experiments in order to investigate a putative role of B-1 cells in a murine model of LPS-induced sepsis. Macrophages and B-1 cells were studied in monocultures and in co-cultures. The B-1 cells produced the anti-inflammatory cytokine IL-10 in response to LPS. In the B-1 cell-macrophage co-cultures, production of proinflammatory mediators (TNF-alpha, IL-6 and nitrite) was lower than in the macrophage monocultures, whereas that of IL-10 was higher in the co-cultures. Co-culture of B-1 IL-10(-/-) cells and macrophages did not reduce the production of the proinflammatory mediators (TNF-alpha, IL-6 and nitrite). After LPS injection, the mortality rate was higher among Balb/Xid mice, which are B-1 cell deficient, than among wild-type mice (65.0% vs. 0.0%). The Balb/Xid mice also presented a proinflammatory profile of TNF-alpha, IL-6 and nitrite, as well as lower levels of IL-10. In the early phase of LPS stimulation, B-1 cells modulate the macrophage inflammatory response, and the main molecular pathway of that modulation is based on IL-10-mediated intracellular signaling. (C) 2010 Elsevier GmbH. All rights reserved.